1. Is not very logical that a soldier has bandages and he knows how to use them even though they shot on his leg.
In the eastern front, there are a lot of civilians who were trained by the soviets during 1 o 2 days, is not very rational that they have how to use bandages.
I see more reasonable and common the existence of medics on the battlefield who could help the soldiers with injuries.
2. In second way, you're agree with your second argument, but we can consider this with another view. In campaign mode, there a persistant war that lasts for months or years, it could be rational that the soldiers, who were saved by the medics in past battles, may return in another battle.