I suggest to limit NM losses for small forces for major factions. In PBEM I had several cases:
1. loss of 1 NKVD unit = -1NM
2. loss of 1 brigade (4 units) = -2 NM
3. loss of 5 units (small force with total 8000 men) = -4 NM
I feel such a big loss of NM is disproportional(at least for RUS game). Red Army in my game is about 700 000, so I wondering why Reds losing NM so bad when a tiny fraction of their forces lost - and NM drops have accumulating impact on cohession, it means fighting ability. I suggest to have no NM drops at all for battles with forces smaller than 5000(or 5 units or so), after that gradually increase it for bigger forces.