Baggronor:
Yes, I have seen people using 20x20mm bases mounted on 25x25mm special movement trays. As long as the size of the unit is matched up correctly, there should be no problem. I even played one guy who had 40k Daemons on a 25x25mm regiment movement tray, the final size of the tray was right so no problems 
This is what I plan to do when I use my CDs as WoC.
CheTralfara:
How are you gonna fluff justify the CDs increased movement? I was thinking you could call it the mark of hashut⌠the benefit being +1 to the original chaos dwarf movement characteristicâŚ
Thommy H:
You donât have to move the full distance all the time.
Revlid:
You don't have to move the full distance all the time.
Thommy H
Thus crippling them.
In my version of this, I just didn't use Chaos Dwarf Warriors. My only Core choices were Marauders (mounted and on foot) and Warhounds, which I used as Marauder Allies or Hobgoblins, whichever took my fancy.
http://warhammer.org.uk/phpBB/viewtopic.php?f=5&t=51944
Thommy H:
Thus crippling them.
Hey, I didn't say you could do it and
win - just that the additional inch of movement is not
necessarily a problem for purists.
Baggronor:
To be honest, if youâre using units of Chaos Warriors, you probably arenât fussed about being competitive 