Advice on army for my mage

[ginolard]

Am playing through for the first time as a mage. I made an initial boob in that I didn't realise how you accessed the Spirits of Rage so they are a bit lower level than they probably should be.

Anyway, I am wondering if my army could be better. I am in The Land Of The Dead and struggling.

I'm a 20th lvl mage with 12205 leadership

Army is

142 Dwarves
54 Cannoneers
15 Ents
200 Royal Snakes
6 Giants

I tend to find that I get overpowered easily if my big damage spells don't take out a hefty portion of the enemy. I'm thinking of dropping the Giants for some lower level creatures but which ones?

Any tips?