I would have to say either a spy, to get close and do some damage before getting completely ravaged, or a sniper, to pick them off at a distance so that I don't get completely ravaged. Also, you said snipers kill with a headshot, so the medics won't be very helpful.
Somthing i forgot to mention, to instantly kill a heavy as a sniper you have to aim for the head and it hased to be fully charged, the medics also hide behind the ones there healing, making them harder to hit, they also have a ubercharge which takes 3 rounds to charge making them invincsible for 1 round.
Attack 2/10 speed 6/10 health 5/10 special can build sentry's, dispensers and teleporters.
Oh, i forgot the tutorial. to make a sentry you need metal, you can get it from any ammo suplies, and that goes for upgrading and building everything else. Spys can zap sentrys so you better hit them in time. you also got to give it a good place.
Sniper Speed 9/10 Attack 9/10 health 2/10 special a charged head shot can instantly kill all classes Nickname: Angel of Death
Tutorial: as a sniper you are a very weak class in terms of health but to a ton of dammmage if you charge, However if your out in the open you will quickly be killed. your a outside class and the first map your doing suits you well. Happy sniping!
The blue teams gathering their stratigies, this time there doing a heavy medic charge, for now your bots are: a pyro, and a medic.
The blue team has 4 bots 2 heavys 2 medics (for now). im being VERY generous for one of these bots that you have on your side, exploit this advantage and you may win.