If you want to produce a unique flavor profile from multiple strains, try selecting 2 yeasts that are active at approximately the same temp.
This. Ale a lager yeasts have very different temp ranges, so it would not work. Or should I say not work very well. If you set it to the lager tempthe ale yeast would not really do anything. If you set it to ale temp then it would be too hot for the lager yeast and produce off flavors.
I did a Tripel that used 1214 and 3787 and it turned out great. So mixing yeasts can work.