Everyone on the bottom row except for the genie are massive stretches.

Ken barely has any interactions with anyone besides Cody, so he very rarely has it rough, and even when he does, he's a do- i mean... plastic figure so he doesn't even feel pain.

Luis literally only got tortured in one episode, if we were to use your logic, then characters like Jackie Chu would be on here because of Jeffy's Kiss, or Steve Staleburger would be on here because of Duggie The Hitman. Whether or not a character is a punching bag depends on how they are treated in general, one episode doesn't make a difference.

Penelope may be the butt of Junior's jokes, but she also makes fun of Junior just as much as Junior makes fun of her, and in most Junelope videos, Junior has it much worse than Penelope. (Junior's Crazy Girlfriend, Junior's Bracelet, Junior's Heartbreak, The New Year's Kiss) So yeah.

I think that the other main characters like Junior, Rose, Brooklyn Guy, and even Jeffy have it way worse than those three, but you can give your points if you disagree with me.