A realism VS fun discussion again? For me, realism is fun.
Track individual soldiers' ages, make them grow weaker and retire over time. Not that it will ever matter, given the lifespan of the average trooper in M&B.
Track each individual item's state, let it degrade over time and with use, and add new game mechanics around preserving food and repairing equipment.
Make it so that each soldier actually needs to get their equipment, so you either have to provide it for them or they need to be given enough money to go out and buy it.
Then recover the equipment of all slain soldiers after a battle (or your share, anyways) and cannibalize it to repair your own.
Overcomplicated, cumbersome, pointless, too much work? I don't care, I'd enjoy it.