Makes perfect sense, and I am only shooting brass that was fired in my guns or bought brand new but having said that, up until this point when I pull out a bag of brass I don't know which weapon the brass was shot in. I have an Encore barrel for every caliber bolt action rifle (excluding WSSM) and my boys have matching 700's in .243. I have learned a lot just reading about reloading so far, with obviously much more to learn. But from now on, I will know to keep fired brass together and labeled with the barrel it was fired in. I'm a computer engineer by trade, so best practices and logical thinking are part of my daily grind, which means that reloading is right up my ally. I'm just kicking myself for not getting into this 20 years ago.
Yeah, with multiple rifles in the same caliber I would suggest full length sizing and not to worry about keeping brass separate to each gun. What I would keep up with is how many times fired each piece is.
It's funny but I have seen it many times, a load shows no signs of pressure when fired with full length sized brass. Use a piece that has been neck sized only and the primer is now flattened....and you are scratching your head saying "but this was fine last time". What people don't think about is v when you full length size you are studying the case smaller than the chamber and the brass can expand to fill the chamber. Once it's been fired its already expanded to fit the chamber and where is pressure going to go.....either push the bullet out, or push the primer out, or both. Also not all chambers are exactly the same, and one round in one rifle might work where it won't chamber in another, even if they are sequential serial numbers.
But if you can keep everything segregated and separated then go ahead and neck size only.....but I don't have any lol.