Ah! +10 would be plenty. That was my original thought, but you seemed to have a +3-5 thing going, so...
No, the bonuses certainly shouldn't stack. If you name them (I can't look back at the spell right now), and don't specify stacking, then they shouldn't.
ie, +10 inspirational bonus/+10 morale bonus/+10 community bonus/+10 enhancement bonus...
