Who is buncha places?
While that seems a nice definition of variance, I am really not sure it applies, especially when describing Omaha.
Based on any specific hand, not necessarily on sessions, but sessions are made of hands so....
When we ask what is the mean winning hand in Omaha on a graph it will always be closer to the nuts in Omaha than any other game. So that standard deviation chart will look unbalanced. Rather than a nice bell shaped curve, it will look more like a teardrop lying on its side and cut in half. Same with the slightly different graph of the Average winning hand. If we play Omaha, we should know that. And if knowing something becomes the main tool against variance, then we should be able to minimize variance. We have 6 hands in Omaha, and if we can't make something pretty close to the nuts, then we are chasing, (which will happen in all forms of poker) and we should have a good knowledge/feel of expectations in poker (Omaha odds
are not the same as Holdem odds) to chase.
So, again I mention, that there is so much available info in Omaha, compared to HE or any other variant, that we should be able to make easier good decisions in Omaha because we are loaded with that much more info. Omaha is a chasing game tho, and catching happens a lot more often than in HE.
So I maintain that HE has more variance because we are making decisions based on less info.