Balance changes aren’t nearly as difficult or paramount for co-op as they are for ladder (which is a good thing for co-op and its players). I don’t think they’d even necessarily need to rework and rebalance all the commanders to implement a talent tree system. I believe that the devs and the community can come up with ideas that are highly unique, cooly compelling, and really fun to use and experiment with, all while still being reasonable in terms of strength / balance.