<<The 2 hold patterns for light/medium and heavies, would appear on the broad brush to be plausible, but logistically, drawing a single queue from 2 multi-variant sources would be difficult.>>
I don't fully understand what you mean but be advised that a vast number of airports around the world have similar procedures. At Heathrow there are 4 stacks, all of which are used for a multitude of aircraft types. There is no difficulty at all in producing a single approach sequence from "multi-variant" sources.