Wifstrand:
So the Legion of Azgorh entry for the Sorcerer-Prophet refers to the Storm of Magic entry for the Lammasu.
I suppose the Lammasu in question, when used as a mount in an LoA army is eligible to select the two upgrades from the SoM entry? The Tail Attack option is debatable, since the rules for such attacks are found elsewhere in the SoM book and not in the core rulebook or the Throne of Chaos book. But what about the Breath option? And the level 2 option?
What have you been doing?
BeeZharr:
I’ve been wondering the same thing.
The way I would interpret it would be that it can’t take the upgrades. It does not explicitly state you can’t, but no other mounts (as far as I know) can take their SoM equivalent upgrade so I would assume the same is true here.
Wifstrand:
I think that’s because all the other monster mounts used to only exist as mounts for characters in the army books until Storm of Magic came along and gave the monsters a new incarnation.
In our Lammasu case it’s totally different - it started out as a SoM entry and rather than reprinting it, they chose to simply reference it.
Thommy H:
There’s no reason you can’t take the upgrades. It says to refer to the SoM entry, and that entry includes the upgrades.
BeeZharr:
Letter of the rules - yes. Spirit of the rules - I’m uneasy with it. The upgrades in DoN are obviously for SoM games, I think this is just an oversight by FW. The Great Taurus can’t use the upgrades.
Wifstrand:
I agree with you on the letter/spirit thing, that’s a really good way to put it.
Of course the Taurus can’t use the SoM rules, since it isn’t LoA doesn’t refer you to the SoM book for the Taurus rules. Well that’s my way of seeing it.
If we can’t use those upgrades for the Lammasu (tail attack/breath) then by the same logic we can’t upgrade it to a lvl 2, which is bad news since that one extra level on a Shadow wizard is pretty important.
Thommy H:
Letter of the rules - yes. Spirit of the rules - I'm uneasy with it. The upgrades in DoN are obviously for SoM games, I think this is just an oversight by FW. The Great Taurus can't use the upgrades.There is no precedent anywhere else to decide one way or the other. Nothing else refers to the SoM rules in this way - I'm actually mystified that they would have reproduced the Taurus rules verbatim, and then just referred to SoM forthe Lammasu. Why not put in full rules for both, or neither? Unless, the intention was to restrict upgrades for the Taurus but not the Lammasu, which is the only reason I can see for it.
BeeZharr
BeeZharr:
I think the reason is models. The two units that refer to other books have citadel figures. FW produce a Taurus model, so they can print rules. They don’t, and won’t, do a Lammasu or Hell Cannon model, so were probably barred from printing the rules for them.
Though, as you say, it doesn’t overpower it so is probably passable. One for the FAQ list methinks.
ryanamandaanna:
My concern with the upgrades is that the Lammasu is already more expensive in LoA BEFORE the upgrades. why, oh, why didn’t they just leave it as “refer to SoM” including the point cost? 
Thommy H:
No one knows! It’s certainly not because SoM monsters are generally cheaper, except as an artefact of changing editions. A Wyvern costs the same in SoM as it does in the O&G book, for example.
Nicodemus:
OK, I’ll weigh in here…
I’m not entirely sure why there’s a difference between the GT having its rules printed in the Tamurkhan book and not the Lammasu or Hellcannon. One possibility is that FW was fine with the Lammasu and Hellcannon rules as presented and there’s some rules differences anyway between Tamurkhan and the SoM GT anyway… so to clarify everything (without getting too detailed on points costs and exact stats, etc):
Taking a Great Taurus as a mount for your LoA Sorcerer-Prophet costs 30 points less than a straight-up SoM GT without any of its upgrades. Moreover, the Tamurkhan GT does not get the option of taking upgrades like the SoM GT (Flaming Breath and/or Bloodrage). Otherwise their profiles are the same.
An additional word of note on the Tauruses though -the tamurkhan Bale Taurus, which can also be taken as a mount option for a Sorcerer-Prophet, comes with Flaming Breath, +1T and +1W over a regular GT. In this instance the Bale Taurus costs +20 points more than the SoM GT with the Flaming Breath upgrade.
Moving on to the Lammasu, it simply says to see Warhammer Storm of Magic, but it costs +25 points more than a straight-up Lammasu from SoM, but in this case there’s no other differences.
To Summarize:
Tamurkhan GT costs -30 points vs SoM
Tamurkhan BT costs +20 points vs SoM GT with Flaming Braeth (but has +1T, +1W)
Tamurkhan Lammasu costs +25 points vs SoM
So really, you get a break on the Great Taurus, which seems like the best bargain. For the others, you’re paying some additional cost for the added benefit of it being a mount as opposed to a stand-alone Monster… and I chalk most of that up to the cost of it being a mount, plus the extra bonuses they bring the rider plain and simple. The Bale Taurus has +20points for +1T and +1W, and if your rider is your General your inspiring presence extends to 18". Sort of similar idea with the Lammasu, the stats are the same, you gain the increased radius, but I’d also add that in the case of the Lammasu, +25pts is still a bargain as it’s a mount that’s a caster… (see below)
I agree with ThommyH as well in regards to the Lammasu upgrades. You’re paying an additional +25 points to gain access to the Lammasu on p129 of the SoM book, but once you’ve paid the cost to unlock that profile, there’s no reason any of the add-ons should suddenly be unavailable to you. Personally I see that +25 points as a trifle when you consider that your mount is also a caster and has the added boon of unlocking Lore of Shadow for your army!!
That’s my two cents anyway.
~N
P.S. After typing this I would now argue as well that FW set the precedent with the GT. If they didn’t want you to take upgrades, they’d do what they did with the GT - copy the profile exactly as it is in SoM, remove the upgrades and present you with that as your choice.
Thommy H:
For the others, you're paying some additional cost for the added benefit of it being a mount as opposed to a stand-alone Monster... and I chalk most of that up to the cost of it being a mount, plus the extra bonuses they bring the rider plain and simple.Which makes a kind of sense...except that it's not why some monsters are cheaper in SoM than their Armies books counterparts. Again, look at the Wyvern. Same cost in two contemporary books.
BeeZharr:
I’m probably being extremely cynical, but I think the real reason the Lammasu and Hell Cannon rules weren’t included was so that we had to buy SoM and the WoC books to use them. They couldn’t get away with it with the Taurus as they have a model for it. It’s maybe an internal licensing thing, FW is after all ancillary.
I’m still not convinced that FW intended for us to use the upgrades, but as that’s how the rules read I guess that’s what we go with until they clarify it.
Doesn’t the Lammasu have a resistance to magic weapons? If this is conferred to your expensive Sorceror-Prophet on top, that’s worth 25points and far more powerful than just the monster on its own.
Thommy H:
That’s a good point actually - I think it works on any model in base contact, so attacks directed against the rider would also be affected. Fair enough then I suppose, but why not just put the rules in ToC to avoid any confusion? It would make more sense in the context of the Divergent Origin rule, because in SoM there is no separation between rules and army list entry (where you find the points cost) so it’s a little confusing to be directed to another book and being implicitly asked to ignore certain parts of the relevant entry, without any specific information either way. You ignore the main points value, but do you ignore the options (which also have points values)?
It probably is something to do with overlap and models, but still… Just make the WF Lammasu a little bit different like they did with the Taurus. Or don’t include it at all even! This is a variant list with a lot of odd things in it - if we can count our old Lord models as Sorcerer Prophets, why not Lammasus as Tauruses?
Groznit Goregut:
Not including rules for the Hellcannon can be seen as just keeping that weapon in the other book. If the WoC rules get updated, then the FW rules do, too. It is easier from a maintenance perspective to leave something in another army book the way it is. I haven’t heard about the Empire stuff in the book, but I would imagine that a lot of it would just point back to the Empire army book. What happens wen one of those books gets updated? Which rules would you use?
I have no idea about the GT other than them selling the minis and someone crying "you just didn’t include the rules timbale me buy the other book! You sell the mini, now give me the rules!"
I also agree that you should be able to take the upgrades.
It is a cool thing to negate magic weapons on enemy. The Prophet isn’t a wimp when it comes to combat and negating items means you could kill some tough lords, like reverse ward save DE lord.
Hashut’s Blessing:
Regarding not taking the tail attack because it’s explained in SoM and not Tamurkhan - loads of rules aren’t explaine din Tamurkhan (Flaming Attacks for example). Also, to have the stats for the Lammasu, you need the book, so you have the rules anyway.
It depends on the wording - if it says use the stats and rules from SoM, that’s what you do if it says to refer to SoM for the Lammasu, you can use it all.