Nah, even though he even looks like roadkill walking, there's jokes & gags aplenty to be made using Weasel before he's offed. Yeah, he'll (probably) buy it, but only partway through/late.
I'm picking Javelin - the idiot in the super bright yellow & blue costume.
I don't see him adding anything to the team. He throws javelins. That's pretty redundant on a team where one guy (Bloodsport) uses actual guns & is standing in for Deadshot and you KNOW the other guy-who-throws-things (Boomerang) ain't getting killed.
Hell, he's not even good for sight gags like Arm-fall-Off Boy is. All he is is a bright shiny (and redundant) target.