So you believe sacking him now and appointing a new manager would cause less disruption than have him for (at least) one more season and judge from there onwards - all assuming Levy doesn't fully trust him.
We'd effectively be entering a self-imposed transitional season, and to me that just seems pointless.
When a club is singing from the same hymn sheet from top to bottom, that's when it is successful. When the manager has the respect of the players and board alike and everyone buys into that vision, clubs will be relatively successful more often than not.
He's either the right man for the club, and we then enter a strategy as a club for the next 3 years and beyond, building on Redknapp's strengths and allowing him to flourish and function and put his plans into place, or we let him go and bring someone else in who we do trust to implement some form of plan.
Keeping Redknapp if he didn't have the respect of the board would translate to the players and undermine their respect for him. It would then be all too easy for disharmony to foster and as soon as results don't go our way, rather than pull together the blame game would start and it will take longer to get out of the rut. But ignoring that, we wouldn't be able to put a plan in place. We'd be going from window to window, trying to patch up the squad as we go, with no clear definition of the strategy we are employing.
Milo is totally right in my view. Harry could be the wrong man now and should go, or he could be the right man next year even if he finishes 6th. But if it's deemed that he is the right man, then he should be backed. A new manager coming in with a pre-season to prepare and a balanced squad that needs only subtle improvements wouldn't cause disruption. More disruption would be caused from not fully trusting a manager and then letting him carry on into the season to see how he does, and then as soon as results go against us, get the feeling that the lack of trust was justified and then letting him go early. Which would be more likely to happen if they didn't trust him for sure.
I just don't see why you'd rather a club not really sure of where it wants to be heading in the medium to long term than a club that gets their man in place, backs him and works together on a clear strategy to attain their targets. Why would you want potential uncertainty? Why would you want questions being asked? Why would you want a lack of trust running through the club? It just makes no sense to me. Almost every successful club has trust and belief, and togetherness working down from the Chairman and the board, through the manager and on to the players. Almost every club failing to live up to expectations can be traced to not having that very same thing at some point in the chain.