We’re almost certainly getting it wrong because the streaming services are getting it wrong. Believe it or not, all labels supply is a name – “Ian Brown” – not an id. It’s unbelievable. It is not uncommon for streaming service artist ids to contain albums from more than one same-named artist. The most popular artists naturally get sorted out more quickly, e.g. Michael Jackson, Nirvana.
I’ll ping our streaming partners and see if they can figure it out.