Make enchanters great once.
I tried all sort of them, and it just doesn't feel strong. Also at the end in the statistics their numbers remain low. Even if i combine the healing done+ally shielding+damage done. They are pretty far behind compared to any damage dealers. And their mitigated damage, and damage taken also low compared to any tank.
BuT thErE Is tHe Cc!!!
Yes, and so are half of the roster. Tanks, mages, some assassins, even certain ADCs. Hell some of these champs has harder CC, than most enchanter.
Get Soraka as base, and make all enchanters rival to her healing power in some way. Either with shields, or heals, or CC. She is the only enchanter, that can rival damage dealers' damage with healing. And even with that she becomes considerably weaker on higher elo, because the very limited self protect.
Get their numbers similar to damage dealers, because they are not tanks. You won't survive longer as a Lulu, than a Garen. But a Zed without ult can outdamage your E twice with poke, and Lulu needs some serious timing to block that poke.
BuT tHeIr WiNRaTe!
Is nowhere close to any other role's top ones. Support in general is quite weak, but the enchanters doesn't even have numbers to prove with. Tanks can show damage taken, or mitigated damage. Pokers can show damage dealt to champions. Both can rival to similar champions from other roles, or at least be relevant.