It doesn’t have to be in the first fight. And no, it’s customary for the new fledgling to join the clan of the vampire that bit them, but they still have the free will to move to another clan (which also means they can be taken). I’m mostly just trying to think of ways to give Vail more of a purpose in the main conflict, since he hasn’t had room to do a whole lot up til this point outside of the romance. The action is mainly happening on Victoria’s side.
I could also see everyone taking refuge somewhere further away after the battle if they lose, because the Wynters would want to “clean house” to make sure the Hygraces aren’t a threat to them anymore. During the fight is when Victoria would be injured (if she still is), yeah? If so, I was thinking Vail would notice and stop whatever he was doing to take her away from danger before he realizes she’s already dying and turns her. From there, maybe some of the others from his clan and/or the Order run after the tide turns in favor of the Wynters, and they flee together. Victoria would wake up wherever they end up taking sanctuary a week later.