The range of the annihilators are to short, you can probably shoot only ones and where you’re lucky twice in a game. I would use normal warriors and more spear chukkas. As for another eartshaker, I’m not sure. I’ve tried one eartshaker a couple of weeks ago and it didn’t impress me.
stick with your guard and the 2 blunderbuss units in 8th there brilliant in 8th units are bigger bigger the unit bigger the mess when you shoot at them work in with it dropping there T so your wound rolls are 2+ (shadow spell). big units knights orges chariots bolt throwers and earthshakers can thin them down
stick the hogboglin iside the guard ( not really a fluff thing to do ) but you can hide the mage from combat 5 wide bsb 3 full command and hobgoblin and you can still cast useing the true line of sight rule