The only thing I would argue there is, without him that performance wouldn't happen. It was happening frequently with Fernandinho at the start of the season.
Currently he deserves an extension. If he's working hard and has abandonded or rather we've disbanded his clique I'd have him for another season.
As you say, Clichy, Zaba, Willy, Navas all look to be on their way out. There's a decent chance Delph & Fernando will follow too.
They will surely be replaced by younger players.
Toure's current form offers the opportuntity to rotate with Fernandinho, interchange with Fernandinho and even rest Silva & De Bruyne a little more against the cloggers.
Both Toure & Fernandnho have shown qualities in the more advanced role and defensively.
Fernadinho could also be deployed elsewhere. He's always looked excellent at centre half inhis limited minutes there.
He is much better than Fernandinho at the base of midfield when we have the ball. Fernandinho for all his quality simply can't do what Yaya does when it comes to possession - making himself available constantly, beating a pressing defender or two, popping the ball off to someone in space and moving the ball forwards. His passing range was integral to it as well, as a number of the through balls which really got at Spurs were early balls from him - with Fernandinho we have to get it to Silva or De Bruyne and it slows it down.
I love Fern, he's our best defensive player by a mile, but Yaya is just different class with the ball.
I'd like to see the team from Saturday with Fernandinho in the hybrid RB/CM role Zabaleta had.