The weakest castle in Heroes of Might and Magic IV!

I usually took two (!) priests for the Life skill. I would level up resurrection for one (and then buy or develop tactics), and max out magic for the other (EXCEPT for resurrection), and then I would take something else... either another school of magic, or combat skills, or something else. And I usually leveled up Combat for each hero to some extent (to increase their defense).

For the Sylvan faction, the druids are valuable for their buffing spells and quicksand, not for summoning.
Haven is the best :)