If you’re going to claim that 4* + 20 is basically a 5*, and that a 3*+20 is basically a 4*…
…then you’re comparing a 4* Brienne to a 5* Boldtusk/Kiril.
Isn’t that the same comparison as the current 3* vs 4* versions? Wouldn’t BT or Kiril still be preferable?
…especially since everyone else will be leveling up their own heroes in exactly the same manner. I should imagine that, just as before, the only reason to level up Brienne will be to have a good +Attack buff in the Rare level Challenge Events where you can’t use anything over a 3* hero.