I recently checked out the release version of Arma 3 and played the new tank showcase. Apparently I encountered an issue which stopped me from completing the show case about 6-7 times.
https://www.youtube.com/watch?v=vDxWSc4gUG4
This "feature" happend to me 6-7 times in under 10 minutes and all i order my AI driver was to stay in formation. I know there might already be an issue going around about the needed tweaking of the physics engine and so on.
Still i don't think it's a very good idea to release a showcase which tries to feature the new driving physics when it's clearly not ready.