New to Panzer Campaigns, have many questions... Let's start with HQ's

[Xerxes77]

In practice the end result seems to be that keeping an enemy HQ alive in those conditions is preferable to destroying it. A gamey move maybe, but the idea is to prevent the deployment of a replacement HQ.

Perhaps this is a little gamey, but everyone seems to have a different view on what "gamey" is anyway. 

I would only say that if the HQ sits in a stack with the last units from is formation you might as well destroy it and bag the points as it will never reappear.

If the HQ is stacked with its own formation, yes, there's no reason not to eliminate it. But if it's isolated from its units, it seems more profitable to keep it alive.

Probably not a very common situation anyway... but the OP has an even "gamey-er" option to break out of the trap depicted in the screenshot, short of mounting a rescue operation: in his turn, use the HQ to assault the adjacent enemy units. The game will show a warning that HQs cannot assault, but it will still draw opportunity fire. At some point the HQ will be destroyed and eventually a brand new replacement will appear behind friendly lines