plain up healing is boring, I think. Here are some ideas I think are interesting. Hopefully this sort of thing doesn't annoy developers but anywho:
1. Pirates take less damage temporarily when on grog and have more potent attacks. When the effect wears off, all the damage they didn't feel during the grog comes back though... buys time to run.
2. Vikings get buffed regeneration. Kinda like berserkers in AoE. It makes sense guys!!!!
3. Knights get temporary invincibility. Either very brief invincibility or the power has to be quite costly, or maybe the priest has to concentrate on one guy at a time. Not sure how that would work honestly...
A little bit of differentiation between the sides!
Also developers, do you like suggestions or do you just think "Make your own game dinah!!!"