@mr-t I don't think you get whole point there mate!
Please do elaborate what you are unable to do?!
I have finished all maps with 1* vehicles on hardcore, several times over.
Seeing as how multiplayer servers are mostly desolate, barely finding one or two players i cannot achieve that.
But in the few games that somehow managed to finish (without the host exiting after 5-10-15 minutes) i actually helped get across the other players.
But more to the point, please present one specific case and what you want to do and i shall walk you through step by step.