LikwidBacon has a point, actually. The kits should be adjusted for balance according to the kind of mode you play. This adds variety to the game, giving players different approach options while maintaining an even playing field. If they didn't change the kits according to the gamemode, almost everyone would be using the same one or two kits and not giving regard to anything else in the roster, leading to pretty much the same game. Different kits to choose from could also open up to new strategies. What's more, I don't think enchantments are very hard to put into a plugin. If the process of making kit rosters via plugins is anything like typing in a command, enchanting is just another data tag. All you need to type to give a player a prot 5 leather tunic, for example, is this:
/give [player name] leather_chestplate 1 0 {ench:[{id:0,lvl:5}]}
Not hard at all if I guessed right about how plugins work.