There are currently 12 characters vaulted:
Beast
Black Panther
Black Widow
Colossus
Daken
Doctor Octopus
Iron Man
Magneto
Psylocke
Ragnarok
She-Hulk
Thor
Those would divide neatly into 2 six-person groups of Lightning Rounds: Avengers (Beast, Black Panther, Black Widow, Iron Man, She-Hulk, Thor) as one, and others (Colossus, Daken, Doc Ock, Magneto, Psylocke, Ragnarok) might work, or some other way of dividing, even doing a three-way split, but that would make everyone available in one for or another, plus solve the “undesirable lightning round tokens” problem if they were the only 3*s available in Lightning Rounds.
To use 6 characters, you need to change the rotation schedule after the first set. The old Heroic lightning rounds were miserable for me as the time slots I was able to play (6 PM-10 PM approximately) had the worst characters for me at the time. With 5 characters rotating, at least you get a different character the following day.
I agree, actually, and prefer the 5-people rotation. But this would only be a problem occasionally, and it’s not like it’s happening this month. Given that there would probably be 14-15 characters by the time they implemented it, I’d think 3 different groups of 4-5 would probably work.
I agree that the absence of actual ‘rotation’ made the 6-member rounds frustrating. Having the fight on the 9’s be the same character 4 times per week (AM and PM) was irritating. Even with the 5-man rotations, having them occur in the same order and start with the same person every week was unfortunate for people with constrained time. Offset the start by 1 every week, or change the order each week; either would help.