Damn that sucks, my troops are stuck at 28% cohesion then. Yeah it would be awesome if it would improve over time by a small amount.
It does improve over time.
Unit Status Report (21 hours, 6 minutes ago)
After resting, 1 of your wounded men recovered by themselves. A total of 1 men are once again ready for battle.
Cohesion of your unit increases by 3 %.Wear and tear causes 2 % damage to your unit's equipment.
Morale of your troops rises by 6 points.