How many times do I have to keep repeating this? Season 1 Mark and Allen have
NEVER fought together;
they only fought each other once over a misunderstanding, and that was it. Allen doesn't appear again until the very end of the season's last episode. There,
he and Mark just sit on the moon and catch up. According to the Versus Thread Rules,
a 2V1 match can not be applied if the two characters in question have never canonically fought together before. In Season 1, the only people Mark has canonically fought alongside with were
Titan,
Atom Eve, and
Omni-Man. Allen doesn't get to fight alongside anyone until Season 3,
when he breaks out of the Viltrumite prison with Battle Beast and
Omni-Man. The only time Mark and Allen fought together,
or more accurately, in the same space as each other, was in Season 4, but by then they had undergone significant changes in strength and character, making them entirely different from their Season 1 selves.
If this match was Kaneki fighting Season 4 Mark and Allen, I wouldn't mind at all, though the Invincible profiles haven't been updated yet (Given the existence of a
big new feat), and they'd one-shot (
7-A VS
High 6-A).
This match is basically akin to pitting Kaneki against Saiyan Saga Goku and Vegeta. Ignoring the obvious power difference, this match wouldn't work because Saiyan Saga Goku and Vegeta have never fought together; they only fought each other once, and were enemies at the time. Not to mention, Vegeta would rather ditch Goku than team up with him (Like he did on Namek) or try blowing up the planet to kill two birds with one stone (or Galick Gun in this case).
But back to the point. Because of the Versus Thread Rules.
This match is invalid because Mark and Allen have simply never fought together in Season 1.
You even acknowledged in your revision that they've never fought together in those keys.