After trying to find a good balance I realised that the indestructible HQ's made it too easy and the sling loadable HQ's made it too hard sooOOoo...

Each side now has a destructible vehicle which means that you can now lose if your HQ is destroyed.
This feels like the right equilibrium and makes it much more realistic.

So you can now win the game by destroying the oppositions MHQ (if you can find it) so hide it well :-)