Since IPs have now been limited (especially for the USSR) with the revised rules and are more Event Card driven, I think the "abandoned" requirement should be relaxed. It allows for the use of the IPs in more critical locations well to the rear before the fighting gets there.
Any thoughts on that?
There is already a Soviet Set-Aside Card--"Mother Russia Wants You"--that gives you six IDM and a Garrison. This may not seem like much, but we don't think the IDM's should be so easy to get. Alan and Jeff were too macho (or something :D) to build these, but finally saw my IDM's and we all agreed we wanted less of them. It was fun to build them, but attacking vs. less of them is exhilarating for me. There is no longer a limit of only two Garrisons being built per turn, so it shouldn't be too hard to tend to fewer IDM's. If in Cities they aren't abandoned when in EZOC's. I don't remember if they need an OLOC.
I know that at start, there are rear area units there. It is that they quickly find their way to the front to face the deluge on turns 1, 2 and even 3. So it thins very fast. At least that has been my experience.
Certainly IPs need to work in the big ETO picture. Maybe keep my idea in your possible toolbox, that having an Event Card for USSR that is just an IP build (with nothing else) and make it Set Aside or even Return To Deck. It will allow Soviets, who were known traditionally as excellent at digging in, that ability at the cost of not having other Event Cards.