I always carried one or the other. Frank D always used to tell me I could pair them, but there was always too much overlap for me.
So I have this turnover Roc. Sweet 8X KC Roc. It's funny that it's a turnover Roc becasue 18 years ago those were the most OS Rocs I had thrown, but stuff happens. Anyway, I would cry like a baby with real actual tears of despair if something bad happened to that Roc. If it shattered becasue I was too big of a dumb*** to take it out of my bag in the Winter, I'd cry and then kick myself, then cry some more and then kick myself some more.
So it's gotta come out. Most of my Rocs are DX and any of them could shatter in the cold. So what to do...Oh, yeah. Discraft makes my second-favorite midrange in Z that you can buy all day and won't crack up in the cold. So when league ends (which it did this week) Rocs hit the shelf and Comets are back in the bag. I generally get the Rocs back out in early March so they are back in the bag when daylight savings hits and league starts back up.
I've done the Comets for Winter/Rocs the rest of the year thing for eight or nine years now. A couple of times I was clicking with the Comets and they stayed in all year.
So to answer the OP's question I put three in the bag, two Z's and a Big Z. The one Z is max weight and still pretty stable. The Big Z is mid 170's someplace and is the workhorse. The other Z is a flippy little bastard that I got in a trade, I think it is 166g.
The weight is not all that important since I have another magically flippy Z Comet that is 174g. I have a 177g Z that isn't flippy, but it's kinda flat on top and sometimes gets squirrely and flips unexpectedly. I had a 171g Z that I got right after the Z's went back into production that was sweet-stable and was my go-to Comet for years. So weight doesn't really make a huge deal to me in Comets.
The plastic isn't all that important as I still have some 3rd run LE's and some X's I could put in the mix. I just happen to put those three in this time.