Gundark said:
Also howmany people are in a unit. Using the Regular Medium Infantry from page 61 again are there 50? 500? 5000? Have I missed it?
I can answer this (as I haven't read the entire book in heavy detail, just the "creating a unit" part, combined with the fact that I'm at the office right now):
You did miss it (it's near the beginning of that chapter), but it isn't spelled out clearly: for "normal people" (not 'specials'), the base assumption is 100 people in a unit. However, the number is not specifically fixed - it looks like you can scale it a little and it's not supposed to make much of a difference.
Generally, the battle system for Fields of Blood is designed on the army scale, so the specific number of people isn't as important on this level.
Aside:
I use Fields of Blood exclusively for mass-combat on the army scale (many hundred to thousands+), but not for anything smaller (large skirmish scale). For that (couple hundred combatants or less) I use Mongoose's OMCSII (found in Strongholds & Dynasties). At this scale, the specific number of combatants is important.
Using
both these mass combat systems for the different scales has proven to work very well IME (and IMC).