[Cyriv]

I had to rewrite this idea.
So Basically I Want The Blu Team to be Zombies. The Zombies only have melee.
While Red are survivors.

[PC Gamer]

This plugin will do what you asked for. It forces any player who joins the BLU team to always spawn as a Zombie. It removes their primary and secondary weapons. If a player joins RED team they are no longer a Zombie.

For this to work you'll need to install TF2Attributes by nosoop or FlaminSarge. Here's a link: https://github.com/nosoop/tf2attributes