AT fire in assault hexes

[cjsiam]

So I'm having some trouble with a few aspects of this:

1) if AT Fire is allowed, without ASSAULT---it is not simultaneous----the Russian tanks could take out the PZ without any retaliation---whereas if it
  was considered AT Fire under an ASSAULT it would instigate an ASSAULT fire-fight and the PZ could shot back, either individually or in combined assault.
So allowing AT Fire independent of assault---the dynamic of simultaneous fire is broken...

That is a problem for me....

2) In your example the problem is exacerbated...
  a) The Russians Fire AT while in the Assault square---not subject to any retaliation
  b) The Germans decide to ASSAULT -- PZ either AT fires or combines DF
  c) the Russians (you suggest) get to AT fire AGAIN in their Assault retaliation.....

I think that breaks the mechanic.... 

I'm cooped up in 14day quarantine in Bangkok....my opinion also might change in a week when I breath free beach air....