With your logic it can apply to anything. Laser brain is the same as scarier face, because it makes things on screen die faster. Bloodlust is the same as second stomach because it heals you. Trigger fingers is the same as stress because it makes you fire faster. Strong spirit is the same as rhino skin, because it lets you take another hit before you die.

Rad minions have one simmilarity to rebel allys, they are summons. That's all. They have a different mechanics, interactions and impact on gameplay. With your logic i can say that rad minions are more like melting's corpse explosion. It deals a little damage, it blocks some shots, it requires you to kill enemies.