I prefer my casualties not to recover at all. If you can't stay on 2 feet for the entire battle this time, what are the chances that you'll stay standing next battle? :)

But seriously, I tend to find that horse archers recover very well. Even those with spears as secondary weapons that I later use in melee often get a good proportion of their dead resurrected.

And yes, I'm pretty sure that a Physican = a Herbalist when it comes to healing casualites, and a FM can only have 1 or the other of these. The Casse are lucky in that they can also acquire various druids who increase the chance of casualties recovering. In a recent campaign I had a FL who had 4 or 5 ancillaries who were or the healing persuasion.