Will there ever be a time that the cat isnt with him?
If not, there is no need to continuously track both of your hit points separately.
So the extra 4 hit points would currently put his at 9 of 13.
Sound right?
Will there ever be a time that the cat isnt with him?
I can envision one or other situation when I might send Cinder away to fetch something, or take a message, infiltrate, etc - definitely not something I would be willing to risk many times, but which could eventually be needed here or there. Assuming any of us survive today, of course
Nope, you already answered more than enough