The most glaring issue is balance...it seems like the side that goes first has a huge advantage.
Alternatively, what about the team that goes second in the first round and first in the second round? No matter how I look it at, it
seems like group initiative is a bad idea, but I have my doubts that Larian would institute it if it was such an obviously unbalanced mechanic. In any event, we'll get to try it out in EA and if it is as bad as it seems, I'm sure there will be changes.