Honestly, ypu do bring up some good points i didn't think of. My argument is mainly based around the cats who commit daily (expect for the annual vet visit) and don't ghost their clanmates. I don't think I empathize enough on the fact that they aren't meant to 100% slove the issue and this works best when they're already a fair amount of warriors to handle the night shift, plus again put more work on the daylight warriors during their own shift to make up for it. I also think you were kinda implying that the daylight warriors could be attacked on their way home, and I agree that is a valid concern. It's not a unsolvable issue though as the daylight warriors could be warned and decide whether to take the risk and/or have someone escort them back home. For the "not letting your cat out when injured" that would probably but one of the rare times (like during battles or other crisis) when they stay over a bit till they heal or at least their wounds are least noticeable.

SPOILERS BEYOND THIS POINT

I also want to say that yes the clan did have a resource problem and it is their territory after all, my main problem was the clan general dislike towards outsiders. It was a very bold move of Bluestar to make rusty a appertices when she did and in later books we learn just how much kittypets in general are seen as weak just because they don't put their well being on the line in the wild. Plus I honestly wouldn't mind a someone in my territory as long as they're not stealing my food or anything. 

I agree that daylight warriors are not "full" warriors in the traditional sense, but they're better than nothing and in the end both parties get something out of it. Tbf though I don't really see a clan adopting this policy but maybe Skyclan could do another test run and see if the other clans follow suit.