agree!
I found myself in different battles where my faction lost and I was still alive with my horse archers.
It this case you should be able to retreat and safe your surviving / wounded troops.
Right now, if a battle goes bad for you, you are fu...ed (lose all your army, companions scattered around, lose almost alle inventory items), I think it´s fine if you went down in battle, but now if you survive and have the possibility to retreat.