Having some AoE spells really helps, let some of those paladins get close and burn them.
Make sure you use your potions in time, they heal over time but if you only have 50 HP left they might not heal you fast enough.
Avoid Zandalor's and the Divine's line of sight (fireballs and one very nasty charge), untill you've thinned out their ranks. Charging in equals death xD
I loved burning Zandalor, that loony's screams made me happy.
