I tried recently to finish the outstanding Friendship campaigns, I did not get very far.
The Powerups give my Friends massive skill power, but they are still 1 hit point wonders.
One counter attack from the enemy team and the Friends are defeated.
Since there are only 2 Friends in the first stage, nobody else can assist them in battle.
Here is one of the battles I failed:
Rex was the cause, as soon as Gadget attacks him, his rush attack activates and one shots the team.
So in order to fix this inequity, the Powerups must grant health and armor bonuses to survive the one shot attacks.
I am not paying money for character upgrades just to experience story content.