I see your point, but in the same sense, you could be denying other members lotting rights simply because you scheduled a dual run instead of one.
For instance, if someone wasn't able to make the first two Apollyon runs, then we schedule a dual Apollyon run, they are screwed because they were prevented from attending both of the last two runs. Basically, every dual-run night is guaranteeing a missed run for every single member, which could really screw people over when you can only miss two Apollyon zones max before you are unable to lot. If we schedule two dual-runs for a certain rotation, every single member will be guaranteed to miss at least two runs out of the total.
I guess if we have the dual runs scheduled ahead of time, it wouldn't make a difference, since we could plan around it.
*EDIT* Oh I misunderstood. Basically, dual-runs will be counted as one single run TOTAL. In other words, if a dual-run is scheduled for Apollyon, you need 2/3 runs attended to lot instead of 2/4. That still really makes it even tougher than it already is to maintain "50%" attendance for those of us who can't regularly make a certain day, since it will end up being "66%" anytime we have enough people for a split run. :/ It's still better than the alternative, i suppose.