This is definitely an improvement, but I think there are still problems.
The team boss is often just a lot of loot for one person, especially when the guild has a wide variance in power. A top player can easily solo the team boss until it’s too strong, and nobody else can do anything, except get a few rewards if they scratch the boss before it’s dead.
Hero powerups are so dominant that it feels pointless to invest in anything but a team of 5 in the current color. Changing my lineup to counter different abilities doesn’t matter when my team is so much stronger. And when I reach the point where defender power is closer to my attacking power, and abilities start to matter, my other heroes are so far behind in powerups that it’s still better to just keep buffing the same 5 heroes.
Here’s a couple random ideas:
Maybe, the team boss should be something different than the individual bosses? Something like a base that spawns a series of N low hp low defense low attack Brains, along with defenders scaled to the attacker. The idea is to let a wide range of players make meaningful progress taking out the N brains, while also making it expensive for a single player to solo the team boss.
Maybe, allow powerups to be reclaimed and redistributed once a day? This would make me feel less locked in to bad early choices when I reach harder enemies later in the week.