your fronts will be ok with a single brichardi for about a year or so. After that the fronts will likely need a six foot tank, so do yourself a favor and start looking for a used six foot tank now. I started out with a 75 gallon and 6 fronts, then moved them to a 135 6 foot tank. now i have just traded all my 75 and smaller tanks for a second large tank, this one is 7 foot. Got to put my other fronts i got in there.
The brichardi pair will be fine for now in a ten gallon as they are slow growing unless the fish are all ready 4 or 5 inch older fish.
Note: if he odd man out is a woman she should be ok with the pair, its only other males that are not so poliltely asked to "move out". LOL
Dont keep julies myself, fronts might eat them in the future if they dont get big as adults. fronts will eat anything that fits in the mouth, usually at night when they are sleeping LOL.