I think you've got to be looking at someone like Norman Cook (a.k.a. Fatboy Slim) for a lot of connections...
The Housemartins - Norman Cook - Beats International - Freakpower - Pizzaman - Fatboy Slim
http://en.wikipedia.org/wiki/Norman_Cook
Some of the Italian producers (behind the likes of Black Box) also have a lot of credits. Queen would also be a fair shout - all but John Deacon had solo success and Roger Taylor produced Jimmy Nail's first hit "Love Don't Live Here Anymore" in 1986