I can see that. But if Luke remains club captain then some of those reservations might be moot.
As a player, I doubt anyone will have any bother with Xhaka being captain, and with Luke being so collegiate, they should work out alright together I think.
I'm not as sure as you are either about a whole new 11. Certainly, last season's players will have to earn their place, but so will the new ones. I'd be very surprised if Cirkin, Neil, Ballard, Hume, Rigg, Roberts, Eli Isidor, Patto , ONien didn't feature well this season, though maybe in a couple of cases if they want to stay. But they don't have to carry the team.
I think we are trying to chart a course that gives us a chance. Still predominantly young, but with some much needed nous thrown in.