There are really no horrible consequences to mixing the yeasts. No real great benefits either, though.
You will get some % of the characteristics of each yeast, however, it is far from predictable without some serious research.
Some yeast strains coexist in a fermantation just fine, while other yeasts will actually eat other yeast strains in a fermentation, so without some serious research, it's hard to tell which of those strains will be the dominant strain and what character from each you are exactly going to get.
Also, I don't know the optimum fermentation temps of the Aztec yeast, but if it does not practically allign with the optimum fermentation temps of the Scottish yeast, you'll have to kinda average them out, which may or may not be advantageous depending on the characteristics of each yeast at various temps. For example, you couldn't mix a lager yeast with a Saison yeast at the same fermentation temp without stressing one of the two and encouraging off flavors, because their optimum temp ranges don't intersect.
All in all, I wouldn't mix yeasts unless you have a good reason for doing so, but also, in the end, if you HAVE to mix yeasts, it's still going to make beer, it's just a bit less controlled than it should be.
So why are you mixing yeasts?
Primary #1 - Midnight Ryeder (Midnight Wheat and Rye)
Primary #2 - Florida Weiss
Primary #3 - Kane-DOH APA (Honey Citra APA)
Secondary #1 - Downtown Flanders Brown (brewed August 2012)
Keg #1 - Raspberry Florida Weiss
Keg #2 - Cinnamon Raisin Cider
Keg #3 - NONE!
Bottled - NONE!