Case in point, it took me years to finally complete the M Frame Slash lineup, but it's a mix of Gen 1 and Gen 2.
You better fix that, Dr. Mann.
Maybe I'm a purist, but I feel like a "set" consists of the originally released items. If other colorways are released afterwards, then those are footnotes to the original set. If you can corral those tricklers as well, then that makes the collection even better.
And let's not forgive one of the biggest wrenches to any side of this discussion - MPH pairs. These guys seems to pop up all over the place with some SKU that was selected from the "never going to need that SKU" pile. I have all the Canteens, but I'm not touching any MPH pairs if I don't have to. I'm not counting them.
Or the Holbrooks on the Vault right now. I don't remember seeing those icons on any releases. Where'd those come from?