Only 3?! All 9 of my yearling boys crow starting at 4:17 on the dot, every day. They trot across the yard to sit under my window and do it. My husband mumbles something about soup....Does he crow yet? I have seven roosters and only three of them crow. Two of my 8 week olds started crowing last week but I have a 4 month old that has never crowed. Maybe you just need MORE roosters lol.
Seriously though, if you can't keep a crowing rooster, make plans early to re-home any boys you might get. It's not fair to the rooster to put a neck brace on (can't even conjure up this image in my brain!), not fair to keep him in a crate or clip his vocal chords. If you can't have them, then don't. Mine crow randomly at all hours, including the middle of the night if they hear a noise.