On my opinion, Logan IS the best option to follow on the Full Moon event.
About the Caleb thing I can assure you that you DO NOT need to bring Caleb back to progress with the werewolves, the alpha and those things, since I have already done it and didn't rescued Caleb yet.
This could be probably because you choosed Bernard and not Logan. Logan relationship with the werewolves is a way more intense, it will lead it to a whole new level of events.
Bit confused by what you mean, Currently Logan is the "alpha" werewolf, but i saved him After bernard I think. But I did save both of them & couldn't get the plot to progress further than that after they were both back in town. The guide i was following implied rescuing caleb was necessary to finish both the werewolf plotline, and get the bareshade upgrades.
But i also couldn't find any way to trigger his first scene without getting bernard to three hearts. I think this was all before the new werewolf events were added? Not sure.
