Because of how the Tom's establish there pecking order, two tom's by them selves will usually fight all the time. Where three usually won't.
Last year we had two tom's and a hen together and the they didn't fight. The were from the same hatch but different breeds.
Larger established Tom's may kill young Tom's if the size and age difference is to much. It' Mostly because they are getting rid of future compentision.
If you don't plan on keeping any of the Tom's, Keep the males from your 25 new ones together, away from any older ones until you are ready to butcher. Doing that will illiminate any possible problems. Although nothing may happen if you don't, it could.
If you do plan on keeping some of the new males, you will need to intergrate them once they get close to maturity. Intergrating Poultry of different ages is a hit or miss proposition. Some time it goes smoothly sometime not.