So I don't remember, when exactly did Ars earn Fahm's loyalty to this extent? Don't get me wrong It makes his a huge badass but did Ars' people ever save his life or anything?
It's not like Kran meant anything devious in paying him, he's way too straightforward of a character and was legit just showing thanks, but the majority of other nobles would give that money as an offer to leave their current lord, and you can tell Fahm's been through some shit since he assumed that was the case