The ABABAB is purely psychological unless the weights are indeed higher for those mods.
It is the same reason they show you the last 10 or so spins on a roulette wheel. If black came up ten times in a row, the next roll MUST be red right?
Every mod roll is independent of previous.
It should take a decently long time to get a max armor set for a 2 skill load out, nevermind multiple loadouts of different skills in my opinion.