Puppies got into it...???

So I've been hearing off and on for the past few days, what sounds like mini dog fights. When I check on the pups, all they do is stare at me and whine to get out. Well this evening, I put them in the whelping box to clean their pen and heard it. Sure enough, Ace the pup I was leaning towards keeping was going after the other puppy, Halo. He was seriously pissed off! SO I yanked him up and put him in the crate for a bit. I put them back together an hour or so later, Halo was trying to relax in their bed and Ace got a hair up his ass and decided he was not going to let him sleep in the bed and went for him again. So once again they were separated.
My biggest concern is how am I going to explain to a buyer that this puppy is very dominant and possibly DA? Am I exaggerating or do I have reason for concern? I do know for a fact Ace has a dominant personality, he runs the puppy pen and decides when his brother can eat/sleep and where he goes to the bathroom. I am very worried because there are people who paid for first pick and they are expecting to be able to pick out their puppy. However, they own one other pitbull and also 3 chihuauhuas, what if they want this puppy? If they do, do I have them sign a contract saying that I told them how this puppy acts and if it does do something to one of the dogs, they bought it knowingly so I'm not responsible? IDK.

That is very common. If the puppies werent "getting into it" I would think there was something wrong with them. Be careful who you sell to and if they really want this breed they will soon learn that this kind of thing is par for the course.
good luck

Thanks, I am glad to know its common! I have heard from other people its not common for pups to behave that way. I am in kind of a rock and a hard place though because I made a pup back deal to the owner of the stud and she gets 1st pick male. She picked the people out so I HAVE to give them first pick and honestly, I don't know if they would know what to do with this particular puppy if they choose him. They have one female pitbull and I don't think they've ever had more than one at a time. I will definitely try and sway them towards the more submissive puppy.

all puppies act like that

As Smoke said if your pups don't act this way its just not natural. Its in there nature! But in time with work they are good dogs if raised right. There's plenty of books to help the uneducated of APBT.

Alright, thanks for the response. Like I said this is my first litter so I really didn't know that they did that stuff. A few friends have had litters and told me it was unusual, but I am sure it happened with their pups, maybe they just didn't realize it. Either way, that little brindle is a dick LOL.