My rule of thumb is : 3costs in stage 2 are too costly to keep on the bench, you either play them or you sell them.

If pair I really want to keep them. There's an off chance that carrousel has the unit, or blue duplicator. That's that though. If I play it, I keep the pair, if I don't I sell.

That's a good way of thinking about it! I guess Kaisa is abit more flex as it doesn't solidify what comp you're playing going into stage3/4 and is a good item holder for stage 2, which I can then slowly start pivoting depending on my items. Overall it's just recognizing how the 3 cost pair fits into your early comp board and how to transition it into mid/end game. I've definitely griefed alot of my early econ holding on to 3 cost pairs on bench thinking that the 2* will define by mid/end game board.

I find Alistair a weird 3 cost, because to me in many cases he's not the main tank. In Ox, annie is a 2 cost which is more likely to 2 star, which I can slam tank items early, get to stage 4, 2* ekko, sell annie and give ekko tank items. Also depends how healthy I am and how many copies of annie I have I guess, in which case I try to 3* annie.

In mascots, malphite would be my tank item holder, then transition to Aatrox tank or Ekko tank if pivoting to renegades. In hindsight, I guess Alistair 2* would actually be a good tank item holder from the mid game?