So you have to actually evolve your heroes to level 20 now to get a Tactical Bonus. Before, it was glitched and it allowed you to get the bonus without that requirement. Wish it stayed that way frankly. Not like it's easy to get all that hero exp just for that.
That verbiage is confusing to me. Do I need to level up the hero I want to play, or the support hero, to get the bonus? So many little partially explained thing in the game, that a slightly better tool tip would do the trick.