I've done some testing with all of these bots, and all of them work pretty fine.

However, only one thing bothers me the most in the mod: MvM Engineer Bot.

This bot works as intended, but mostly runs in and gets himself killed. His intention is to pick up weapons on the ground and bring it back to the thing he places. The thing he places is a bot builder, where he creates bots. It's only an one-time-use kind of deal, then he needs to run in and get more guns.

I have also tested by placing down a BLU Dispenser next to him, and he takes the metal out of it. After he achieves enough metal, he freaks out and destroys the Dispenser. Then he starts building the bot. After the bot is made, he places another builder, and idles. In other words, you need a lot of Dispensers to make this guy happy. I've tested with a RED Dispenser, and he has no reaction to it.

My idea, if this is continued or taken by someone else, is to make the MvM Engineer Bot have infinite / A lot of Metal.

EDIT: Tested the Bot with BLU and MvM friendly with each other: Works just fine. Just wish that wasn't the preference you needed to do to make it work.