Perhaps an official pecking order...
First... Nationality (as this is objective)
Second.. If two bands are from same country, Genre (broad like Jazz, Rock, Reggae, rather than sub-genre like Hard Rock, Punk, Bubblegum)
Third... Sub-Genre, e.g. Heavy Metal, New Wave, Smooth Jazz
Fourth... Related group, e.g. Dave Stewart [Eurythmics]
Fifth... Birth year
I think this might be overthinking it slightly, if it's too complex or the rules are too open for interpretation/opinion, it won't be used or won't be used right.
It could be as simple as If two artists have the same name and are from the same country, then
1. Use the most identifying trait, i.e. group affiliation.
David Jones [UK][Monkees]
David Jones [UK][Bowie]
David Jones [UK][1770s musical pirate]
-----------------
Dave Stewart [UK][Eurythmics]
Dave Stewart [UK][Lives off royalty checks sent to the wrong address]
2. If no clear identifying trait, or identifier considered too obscure, then:
John Jane Doe [N/A][DISAMBIGUATION]
John Jane Doe [N/A][DISAMBIGUATION][1]
My calculations show this would cover 99% of most cases a hundred percent
m.