will my peacocks ever get along?

need more details.type o f peacocks.size of tank..decorations

The acei is not a peacock but a pseudotropheus. Mbuna can be brutal, I've personally never had issues with p. acei but introducing a fish into a well established mbuna tank generally doesn't end well. All you can do is change up the decor, remove the aggressor for a day or two then reintroduce and see if he calms down.

Trial and error, like said above....move decor and tankmates. Eventually you will get the right combo.

If it looks like the one in the pic you posted than it's definately not an acei. Acei's are a type of mbunas.

Peacocks generally are peaceful to each other in my experience, but every once in awhile, you get one very territorial.
Usually once that happens, you have to seperate them forever. It's not going to get better over time, even if you move decorations around.
I had a Benga Peacock, about 5-6" long in a 300.. was a great citizen for years, even with other yellow peacocks in there.
I added 3 more lemon jakes and then he started getting super territorial, and biting other fish. Gave him away to a breeder that was going to keep him with just females..
I don't know if adding the Lemon Jakes triggered the aggression or the fish was just a timebomb and it was going to happen anyhow.

Note, I said a 300 gallon.. even in a tank that big, the aggressor was not happy to see other male peacocks. He even got aggressive towards some of the haps.
So I think you are going to have to move out one of the male peacocks to keep peace. Sorry, but that's the way it happens sometimes. I don't want to give you false hope.