You're imagining the fighting of resource ownership issue. VGAs don't even use an interrupt line. It was a simple matter of the Hercules emulating an MDA whic

You're imagining the fighting of resource ownership issue. VGAs don't even use an interrupt line. It was a simple matter of the Hercules emulating an MDA which had a distinct IO space from VGA/EGA. So you could just slap a Hercules card into a VGA machine and start running software that supported the combination. I don't know anything about Macs but I have no trouble believing it was superior. The PC was incredibly primitive in this area. But that's also why there was essentially nothing to configure when you inserted a VGA and Hercules card into a machine. Their physical configuration is defined by their respective standards, and the standard didn't consider multi-monitor support. It's just fortuitous that Hercules/MDA and VGA standards didn't collide.