I was also suggesting simmilar approach in the past, so it pains me a little to admit it was not too well idea.

Reactions are the reasoun and its a good point ...
I mean IF they would be done simmilar to Solasta ... pause the game, show you all the options at once, let you pick ... that potentialy could work, but im affraid it would be quite chaotic, especialy on higher levels.
I wonder about compromise ...
How about let enemies that are next to each other in initiative MOVE at once ... and then attack one-by-one?