The entire team needs to be rebuilt not just attack and defence. Even Onana at goal makes a lot of mistakes. They should build their team around Amad and Bruno because they are the only bright thing in this team. Other players need to be replaced but i wonder how much they can do in the winter transfer window
I'm sure there won't be much United can get in the winter transfer market. He'll get rid of some and bring in some. Although Amorim may have a list of players he wants. Not all of them will be available to United.
As you said, Amorim may have to get a new goalkeeper too. Who of course has better qualities. Onana has made many mistakes since Ten Hag's season in charge. I'm sure Amorim will have to think about getting a better replacement.