You can't separate the criteria, it's be all, end all
Snoop Dogg is top 20 when you account for everything, including the ghostwriters which would normally disqualify someone but his impact is of such magnitude that it's hard to discount his accomplishments. Arguably one of the best catalogs of any living artist as far as music for performances. He's one of the greatest live acts hip-hop has to offer and he's household name/pop icon. If you said top 15 I wouldn't be mad, when you put him in your top 10 your list starts to lose credibility