I wish they would have included the cooldown on Mow Down. With an HK lead, B2 is probably going to dominate. He'll be taking turns left and right, with HK's leader ability granting +30% crit chance and 50% turn meter per critical hit, B2's unique with a 40% chance to gain 100% turn meter when an ally is damaged or attacks and has their attack dodged, and the fact that his AOE is fairly reliable in scoring at least 2 hits to bring him back up to 100% turn meter to immediately attack again.
We'll have to see, but the way it looks is that he greatly benefits from an HK lead, possibly to the point where the difference between using B2 with HK lead vs without HK lead might be too much. If so, he'd either be OP in a droid squad and decent in non-droid squads, or decent in droid squads and poor in non-droid squads.
Just speculation at this point. We'll see how he turns out.
