The dragons were smart. Even though they were trying to surround Leon, they weren't moving at their max speed. Leon could tell that they were preparing themselves to react in case Leon uses Transfer, and at the moment he does that, they would attack him with everything they had even if they have to sacrifice one of their kind.
Despite the fact that they belonged to different species, the water and fire dragons at least were smart enough to work together to kill the common enemy. Leon noticed that, and thanks to it, he would never fall for such an obvious trap.
