The only function of the iTunes compilation tag in MusicBee requires that the "detect iTunes Comilation and treat as Album Artist" box is ticked in Sorting/Grouping Preferences AND that there is no Album Artist entered.
For tracks with an existing album artist, the iTunes compilation tag does nothing. If there is no album artist and the box in Sorting/Grouping is checked, then you can tell MB what you want the defacto Album Artist to be for those tracks.
I use this feature, leaving all compilation Album Artists blank rather than setting them to Various Artists, and use the compilation flag to treat the Album Artist as "Compilation". I can even then use the "Compilation" album artist in virtual tags and naming templates
For what you're describing, phred, all you need to do is make sure that Year is not part of your Album grouping.