Is it possible for Dread Doctors in Teen Wolf to create alpha wolves since they made Theo a werewolf?
We don't know. But if I had to say, I will say no.
Alpha wolf is a status which you earn by killing another Alpha or by becoming True Alpha, so it can't be crafted. Creatures made by Dread Doctors were not even pure supernatural creatures. So killing Alpha by them shouldn't be considered. Dread Doctors even had Nazi Alpha Werewolf in their custody but still showed no sign of having crafted any Alpha werewolf.
So it's safe to assume they can't.