A very thoughtful article by Robin Candy (Crash, June 1987) in which he reviews the changing structure of the games software industry and compares the business-led publishers of the time to the host of enthusiastic beginners when the home computer phenomenon began.
The "family tree" graphic is a useful reminder of how large companies could hoover up smaller labels and continue to make it look as though there was a lot more competition than there really was. He could have added Mirrorsoft (part of Robert Maxwell's empire) and Creative Sparks (owned by electricals giant Thorn-EMI).
The bit relating to Mastertronic is a little misleading. MAD, Bulldog (and several others) were budget offshoots from the main business but Melbourne House was a distinct branch that was not in any way a "child" of one of the other labels. But it's not important. Carnell Software had long since been incorporated into the MasterAdventurer label which was itself simply a part of the mainstream Mastertronic range.