On your answer on Barbers Dustin & providing men in a feudal system. Does this mean that there’s a multiplier from success? The better you do the more men you have, and failed (the fewer)?

It’s not a straight arithmetical thing, but rather more of a trend. 

If the war(s) are going well, vassals want to be on the winning team (because it’s a good way to get land, ransoms, loot, etc.), so they’re more willing to bet big on success by bringing every warm body they can lay their hands on. 

If they’re going poorly, then you’ll start to see vassals getting truculent about sending men off to fight and finding ways to beg out of it (because ransoms are expensive, supplies are expensive, and burying your men is a dead loss).