You should have no problems whatsoever in bringing in a male, he will automatically be the under-dog with 2 bitches in the house so no heirarachy issues at all. I have a male and females together all bought within 1-2 years of each other, never ever had any problems whatsoever they all get on exceptionally well, bitches are another issue, that can sometimes be hit and miss but if the age differences are appropriate that again causes no issues.
Just remember to also give your bitches time outs from a pup, your bitches will either love a pup to bits or find him irritating at times, so make sure they have somewhere to escape if the pup gets too much, I have always found my Alpha to be indifferent leaving the other bitches to play with the pup and keep it amused, you may find the same that one bitch will take a larger interest than the other, some bitches find pups irritating, (just like some human adults aren't too keen on children) but remember they all grow up, and as adults they should be the best of friends and make a lovely little pack.
Go for it, get your male and I look forward to hearing how you do in the show world.