yeah, it's actually not very fun playing 9 engie vs 9 engies.
here's a questionable way to get the wrangler, easy: google for "Steam Achievement Manager". Make sure Steam is open but all games are closed. Run SAM, click on TF2, check the 3 Engie Milestone achievements and press the hard-to-see button in the top right that saves. Close SAM, then join a server... you get get the new shotgun, wrangler, and the robot arm.
This is questionable, but I haven't been banned and I don't know anyone that has.