The misandrist cult in the remake disposes of all of their male children and only keeps some elderly men around for breeding purposes and to do manual labor. You'd think it'd be a good idea to have a couple of younger guys around for both, since back muscles and erections wouldn't be nearly as robust in a bunch of enslaved octogenarians.
Invoked in the 1973 film with Howie warning Summersile that he will be the sacrifice for next year. Another would be that Howie's disappearance will not go unnoticed by his police force. They could send in an investigation team to find out what happened, and all the townspeople will be in deep shit.
It actually enters Nightmare Fuel territory, when you think about the entire scheme to locate a virgin policeman and bring him over to the island. Is it a coincidence that he's so smug about Howie's absence not being noticed? It's not impossible to have a former islander in the police for and/or a Corrupt Cop who would cover up Howie's tracks for cash. Plus, can you entirely trust Summerisle when he says that it was the worst apple harvest since his grandfather's time, when Howie points out that the island isn't suitable for apples? For all you know, there could have been other (covered-up) harvest failures in the past, each one followed by an unfortunate virgin policeman being burnt alive.
Another fridge horror moment involving Rowan Morrison. Of all the policemen whom they could have tricked into being the sacrifice, they specifically required the only one they knew was a virgin. And Summerisle himself says "A small child is good, but nearly as good as the right kind of adult". Had Howie accepted Willow's "invitation" and lost his virginity, he would have ruined his suitability for a sacrifice, and the islanders, discovering that their sacrifice was ruined, might have actually sacrificed Rowan instead. If Howie were to live, it would be at the cost of Rowan's life.
Why Sister Honey get beat so easily? She's used to the men on the island not fighting back. It was an act though.
Why Sister Beech just stands there and gets knocked out. She let him hit her so they could spot the sacrifice.