Talking about errors, Andrea onana's own is just too much, he can't just go five match straight without making an error that will put his team at a disadvantage, though it's quite true that the defensive lineup of Manchester united is a shambles right now and due to how porous it is now, no goalkeeper in the world that wouldn't be conceding goals back to back, but Andrea onana isn't helping matters because he keeps on making himself a laughing stock in the goal post of Manchester united, and if he is being replaced this season, I wouldn't be surprised because he can't be performing so horrible and be expecting not to be replaced.
Then as for the whole Manchester united team, the position that seriously needs strengthen is the attacking department just as you have suggested victor osimhen and the defensive department of Manchester united team generally, they really needs to be upgraded at the back, and if I were to suggest to the hierarchy of Manchester united, the attacking department and the defensive department of the team is the positions that should be given priority to in this summer transfer window because this Manchester united team is seriously lacking a quality central forwarder and quality and experience defenders.