Enchantment points are currently utterly useless for every other crusader except the one or two you're using for main dps (and for others for the brief period of advancing through stages until you're set up).

There's a couple of ways this could be changed:
1) EP's would boost the equipment for a crusader. For example, 1 ep being a 10% boost to all eq worn by a crusader and hence 10 ep doubling the effect of all equipment. This would better boost the unique roles of all crusaders as per the gear they have access to, instead of just dps crusaders. Some crusaders would suffer, though, like Kaine who's a gold boost but doesn't have access to +gold gear. It would kinda make sense in a way that extra enchantments actually enchanted the crusader's existing gear.
2) EP's would boost the effect of crusader upgrades, so crusaders would benefit uniquely from ep's and reinforce their roles as dictated by their upgrades
3) EP's would boost custom tailored stats of each crusader, therefore reinforcing and improving their roles in the formation. Given that gear and abilities are limited while EP's are not, this would run the risk of being the defining factor of any crusader in the long run, should the EP bonuses contradict gear or upgrade bonuses.

Aaaand as a second side note in the similar vein, the lvl 200 abilities might increase the effectiveness of crusader upgrades every 25 levels, instead of just being a dps multiplier. In that case it might actually be useful to level the buffing crusaders beyond the level they need for last buff upgrade (lvl5 for sasha, for example).