User blog comment:Darksusanoo/(Champion Rework) Caitlyn, the Sheriff of Piltover/@comment-1330314-20150517001113/@comment-1330314-20150517005430

Perhaps it's possible to implement a preparation mechanic without resorting to stacks, but in the end, they're a good mechanic, and using them more doesn't really step on the toes of other stacking mechanics (it's what the stacks represent that's more important). Even the kit you posted has stacks, though, namely on the Ace in the Hole buildup (you need to build 10 stacks of whatever to unlock Cait's ultimate).