Your battalion is within a regiment/division/corps/army that is historically pretty much wiped out but, a surviving battalion out of a corps means the corps *is* pretty much wiped out from the operational perspective. So you're the surviving battalion
That line of thought opens up the question: What happened to survivors from sibling units? You could draw a parallel to what happened with the Black Brigade (Polish 10th mechanized) in that campaign; they replenished many of their losses by picking up strays along the way - that included some armor. (What finally killed their armor was lack of gas not direct enemy action.)
So it wouldn't be unrealistic I think to pick up a replacement tank or two (as well as personnel or crewed weapons such as an ATG) from otherwise wiped out units within the same regiment/division/corps. The tanks might be odd ducks, different than what they're replacing (BT's for example), and maybe, just maybe, that might give you an excuse to pick up one 57mm ATG which would make your life quite a bit easier vis-a-vis german armor.
While the late war German TOE's were the most blatant example of wishful thinking, it was rare for any unit in any army during WWII to have exactly the gear their TOE called for. They all picked up useful things along the way, accepted different equipment as replacements when there was little other choice, and discarded things that were useless (when no one was looking of course).
Just a thought
Brian