The Players should mark each cohort and follower by type: Mage, Priestess, Warrior, etc. And in the House Notes there will be a blurb about each in the command structure. But each cohort/follower is still played by whoever made them.
One change will be that since you ARE nobles, you will be allowed to keep a certain number of your followers as an honour Guard. This is detailed below.
PCs may have more than one Leadership Feat (and thus more than one Cohort). And the Improved Cohort Feat.
Cohorts/Spawn may only have one Leadership Feat and may not have Improved Cohort.
This is where it ends. your Cohorts' Cohort CANNOT have any leadership feats.
There is an arbitrary ruling in place where you can't have more than two main characters (PC, Cohorts, and Spawn) in play in a scene at once. This also applies to followers. You cannot have more then 30CR worth of Followers with you IF you have your cohort as well. If you DO NOT have your cohort with you, you can bring 50CR worth of followers.
This is totally arbitrary, but otherwise people would be running around controling entire gangs with just one Player. Your minions have duties, those not with your PC (or you could walk around with two cohorts and have your PC elsewhere) are assumed to be carrying out those duties.
Cohorts start with NPC WBL. You can augment this with wish economy, so they're not as "screwed" as a normal cohort in a normal game. Followers get only whatever you give them.