[Imp]

Cant do anything directly apart from kill the enemy & avoid areas of carnage.
Your troops morale gets a boost if they hurt or kill something & others witnessing this also get a slight boost.
Of course if they witness their comrades being slaughtered that has the reverse effect.
So sending infantry through a field of burning friendly tanks is not great from a morale point of view.
Other things that effect it.
Losing your HQ or enough of your force will plummet morale.
Being in a trench is a very good morale boost hence the reason they are hard to clear out as rally well.
Keep your formations together, particularly important in an era when radios are rare or fail to work often, the leader should try to stay out of trouble to let him rally troops.

Not covered but you can adjust the standard settings in preferences.
Switching training off lets you set your own morale & experience.
A lot of time went into determining these however & if you want to be realistic I would suggest not fiddling with things like the searching chance if you want realism.
I tried playing with them & they work well just persevere & you will suddenly realise units capabilities.

Playing as Russia is very hard to start with, poor morale exp & lack of AT capability means you don't want to get caught in a slugfest.
Try & keep units alive so they improve, wont take long till they see better & most likely gain an extra shot.
Till then if your struggling buy the odd Guards Infantry if you can., have them follow just behind the regulars that way they avoid being fired on & hopefully see who fired due to their experience boost.