Sometimes you can split a flock, but it's an awful lot of work and expense, especially when taking into consideration that to rehome (or eat) one of the male birds does the job as, or more, effectively and provides for a more comfortable living situation for the remaining birds, without having their space cut in half to accommodate a separate flock.
Only you can answer the question, is one bird worth the extra time and trouble?
If you're keeping the males for fertile eggs, (you want offspring from both males), you can accomplish this easily by incubating eggs, and then introducing the CHICKS to your existing flock. You'll likely end up with the same decision of which birds to cull from your flock in the future with this method, but you will have the genetics of both birds to make your selection from.
Keeping you and your feathered family in my prayers.