Yes, folks have done this from time to time. The results aren't predictable, but it certainly can work. If you pitch both yeast at the same time, one is likely to become dominant. You wouldn't want to pitch a yeast that is killer toxin producing and one that is toxin sensitive at the same time as that would just be wasting the sensitive yeast.
On the other hand, if you pitch one yeast later, the alcohol and effects from the first yeast may really impair/inhibit the later yeast. In that setting a yeast that is good for restarts such as EC-1118, Uvaferm 43, or DV10 is more likely to succeed. However, if the first yeast gets the ABV above 11-12% ABV, getting a second yeast to start becomes increasingly difficult.