i dont have any dats to compare. I bought 1 inch juvies in oct last year and they are approx 5 inches now. They grow slower than most . If i had to describe it i would say they grow slow/medium on a scale of slow, medium or fast growth. If you put a 1 inch oscar in with a 1 inch front the oscar would out grow it in a few months, not so much it could eat it but noticiable. Later on though when the oscar has grown as much as he will the front will keep growing. Up to 14 to 16 is fairly common for monster old fronts, especially the alphas. Younger adult fronts should get 5-6 inches the first year then slow steady growth after that. 9-13 inch alphas are common after several years of growth. They take patience (thats why i also keep some haps and peacocks LOL)
They also do best by themselves with just a clean up fish of some kind etc..breeding fish should be alone.