I like stockpile, i ve already complete The "win 100 matches" contract with it, and Also create Good decks.
But I think The problem of stockpile is its cooldown or even The impossibility to acumulate some charges.
I mean, we have 16-17 turns per match, so, in theory, stockpile gives to you 8 "points" (or buf, or damage).
But in fact, a lot of times you need to use a card thats dont have charges (like a defender, a heatwave and etc) and you lose a lot of the leaders charges.
So i think devs should take of the cooldown or, at least, Let us acumulate The charges. So If you dont use The first charge, after 2 rounds you have 2 charges tp use. I think this problably Will fix The leader ability and Let US use The entire 8 points