The only HoI-ish way I can see to model this is to give "equipment" brigades(tanks, artillery, etc.) a capture chance just like ships have in HoI2. If you encircle a tank division, you might get its stuff. Depending on how shattering works, you could even say that you inherit the division in a shattered form, and have to rebuild it with your own manpower, but the equipment(i.e., division marker) comes free. You can't do it on the vehicle scale, but you can do it on the division scale, with some fudge factors to account for the fact that you don't capture everything. It might be good enough to implement, I'm really not sure, but it's the best I can think of.