Ok your suggestion is interesting but most of these players gift over the possession to opposition like candies to children on halloween which need to improve for it to work .
Hopefully once the summer comes we won't be subjected to Mcfred duo no more.
Ole's 4-2-3-1 was a bit weird. He expected his forwards (AML, AMC, AMR, STK) to play at a very high line with Bruno basically acting as a shadow striker. Meanwhile his defensive unit was expected to play a high line when attacking and to drop ridiculously deep when defending. That caused a gaping hole in CM with the likes of McT, Fred, AWB and Maguire being tasked to provide Pirloesque/Scholesque long range passing to the forward line. That lead to either United giving possession cheaply or else for them to engage into loads of back/side passing up until the forward line lost their patience and decided to drop deep thus disrupting the quick tempo Ole wanted and expected. Both scenarios often lead to the same conclusion with the opponents quickly regaining ball possession and hit us once again. Under such relentless pressure the lines would break, a mistake would be made, the player's confidence will go in the shitters which would then impact them during the next game. It didn't help the fact that we lack leaders and that our captain is a thin skinned overrated player whose got more experience in being relegated (4 times) then the likes of Cruyff, Van Basten or Platini had won ballon d'or (all won it 3 times). Ole knew about this problem which is why he stated that he was searching for 'complete' CMs like Robson and Keane were.
Rangnick system is different. Gegenpressing put the pressure on opponents which means that unless they are quite comfortable with the ball themselves then they will be the ones making mistakes. He's also a big fan of forward passing which, once again, put less pressure on defence. With Rangnick one mustn't be particularly great in anticipation, positioning or passing ability. What he needs to do is to work hard, be aware whom to press and be courageous enough to pass the ball forward. I expect that the likes of VDB and Hannibal will be used more while the forward line will drop deeper from now on expecially Bruno. Once our forward line is more available to the team then McFred and co job will become easier as the workload will be better distributed and they won't be expected to engage in long term passing as much as under Ole.
What concerns me is not whether our first team CM can weather the storm for the next few months but more the downside of Gegenpressing ie INJURIES. Gegenpressing is very taxing especially on a team who wasn't given a solid pre-season to adapt to it. Taking that + the EPL's gruesome game schedule in account then we must expect our lion share of injuries.To make matters worse some of our players are simply unsuited for it. The likes of Pogba and Martial will struggle with gegenpressing while Matic and Mata simply lack the legs to play such physically taxing system. Not to forget that Ole encouraged individual brilliance over team work. The likes of Greenwood and Bruno could basically shoot from wherever they wanted without suffering any repercussions whatsoever. To 'rewire' these players so they can start dropping deep and be more conservative in their game will be tough and will require time.
So to conclude I am hoping that Rangnick will have a CM or two on the cheap under his sleeve and that the club will financially back him. However I won't be surprised if that doesn't happen. January sales are tough and the club might not be keen to invest money on the targets pushed forward by an interim manager.