My read is that the riverlords are unable to muster another military rebellion against the Frey-Lannister contingent holding the If I Cut You Off Chances Are You Handed Me The Scissors Shirt; so, they’ve decided that their only recourse is to secretly back the only threat to the Frey-Lannister hegemon in the Riverlands: the Brotherhood without Banners.
If I Cut You Off Chances Are You Handed Me The Scissors Shirt, Hoodie, Sweater, Ladie Tee, Vneck, Bellaflowy, Kids Shirt, Unisex and Tank Top, T-shirt
Best If I Cut You Off Chances Are You Handed Me The Scissors Shirt
I can only expand on this by relating it to the debate of “Would Ned have If I Cut You Off Chances Are You Handed Me The Scissors Shirt?” I have personally always felt that Ned felt that if they had to put down another Greyjoy Rebellion, Ned would have advocated to replace Balon with his Stark-influenced ward. I could see Jaime choosing to destroy House Blackwood, and leave Hoster as the sole remaining heir, then marry him to a Bracken daughter (his other hostage?). Not just having learned the value of mercy, but make a long term politically minded decision. Hoster even made comments that were somewhat sympathetic to his family’s perennial rivals, mentioning how many times they’d made peace and married.