What process is SCOM actually erroring on? Sqlservr.exe / reporting services service.exe / msmdsrv.exe?
If it is these services what your seeing is normal, tell SCOM to change the metrics as these services are memory intensive. It’s not uncommon to see 90-95% memory usage by these processes.
Now if it is other processes you need to look at what the process is and if it is causing you any issues with it being on the SQL servers or not.
Some 3rd party software installed on a same server as SQL doesn’t really play nice so you need to verify what SCOM is telling you vs what you need to do.