It sounds like the id3 tags for your music files are really messy. I would recommend spending the time to clean up your collection using something like Tagscanner.
The tags are probably of a somewhat mixed quality, being created with different ripper software over time, without too much attention to the details. What I did before I got Roon was to select the albums I wanted to listen to from the folders view in first the Sonos app, later mainly the HEOS ditto. For this use, most tags were irrelevant.
But walking through all files is a big job, and it is only now that I understand the need for it in order to utilize Roon fully. I had a somewhat naive expectation to Roon that it could recognize the albums and display good information about them - but now I know that this comes from 45% own preparation, 45% of other people’s work with sending in metadata to a couple of source databases for Roon, and then only perhaps 10% of Roon’s own work with bringing this together into a good user experience.
There was a popular song being playing in the radio very often during my young years, before ripping and before Roon, where the main theme was something like “This, the priest didn’t say anything about when we stood there” - referring to a marriage and all of its trouble. Now, I am not married to Roon, but still, details unknown from the beginning have started to become apparant 
The system Roon tends to become a hobby of its own, rather than just supporting the music listening hobby. I am not necessarily against that, but it is a surprise.
Thanks for the hint about Tagscanner. There has been many tools mentioned in this thread, and I have started using some of them (dBPoweramp actually being one of them, even though it wasd from another thread, and now MusicBrainz and Picard), and will have a look at Tagscanner as well. I also still own a license to MediaMonkey that I used during some years, and it had/has very good features for bulk operations on tags, so it is still in my pool of potential Roon-improvers.
With the help of these tools, I can probably get a perfect Roon experience after just a few thousand hours of tag adjustments 