My take on Kenny.
He's not good enough for what we want to be, and barely good enough for what we currently are. But we are also looking to replace half a squad of players that aren't good enough, and as a backup who is probably the youngest and lowest paid of everyone we would like to see moved on, he seems like the one position that has some semblance of logic to keeping.
We extend his contract to act as cover between the young fullbacks we have signed for hopefully a long period in the team, and the older fullback is past his best. The idea of spending any more money on another fullback, be that an expensive 1st choice RB who makes the Patterson signing pointless, or another Cuco Martina who signs for cheap but is never going to be 1st choice. The money is best spent elsewhere.
Give Kenny an extension, keep him for a year then sell him. Anything we sell for thereafter is profit and looks good on our books, and at this point, if he goes, we get nothing other than another space to fill with someone who will likely demand a lot more money with no guarantee of being any better.
If the squad was in better shape than it already is, and our finances allowed for it, then sure, by all means, release him and sign someone new.
But its not, and they're not.
Not ideal, but sensible.