Cap & Roster management with a dash of player manager/recruitment officer shenannigans.
You're talking about the same club that signed him to the biggest junior deal ever.
Manly's financials are a mess. Fainu was on too much for their cap balance, plus they (the brothers) were making noise about getting a release (re-Tartak to Fulton).
On a lesser scale, to use as an example, given our roster spots are nearly full- I have no doubt the Tigers want to keep Seyfarth. But, given how the roster is built, given how many spots are left etc...it looks unlikely at this point.
I think the Fainu's moving on is more to do with a quickly dismissed report about their unhappiness with the club's support of their troubled brother.