I would tackle the question from a management angle.
Can you afford to replace expired items in all of your kits when they expire?
If no, fewer kits might be a reasonable aproach.
Can you keep track of which items in which kit are going to expire when? If no, you might need a better tracking system or get rid of some kits.
Do you have the time for regular check and maintenace? If no, you might have to get rid of some kits.
I have a couple of FAKs too. Some sit on a shelf ready to grab and go. Some have their home in the luggage for special activities (e. g. my range bag, my rifle case, my hiking pack) to make sure I do not forget to grab it. Sometimes that leads to bringing more than one FAK. I keep a record of the expiration dates (e. g. sterile stuff in my range bag is going to expire 5/2019).