Do you mean some skins will come with not just an icon set from which users could choose for what to use but a specifically chosen button set?
Yes. A specifically created toolbar button/icon set.
Take your "Darknight" series for example. You might create a full suite of bat-themed toolbar images that you preferred users to instal with your skin for a more complete look. If all options were implemented as suggested, you could make one greyscale set of icons for the entire series and recommend that users turn on "Adaptive" option at 80%, so that they changed colour when using original, red or green versions.
If that's just an icon set that's designed to go along well with the skin, then users only need to set up a pairing between the skin and the icon set (icon subfolder). Wouldn't this be simpler?
I'm not sure if it would be simpler from a coding point of view or not. My understanding from earlier posts was it was something Steven preferred to have as an option built into the skin. I'm sure it would be easier to narrow the choice to either using a skin specific icons set or not. More choices would mean more time and effort required for Steven to implement.
Using the "Darknight" example again, if you already had a set of toolbar images that you prefer to use (some of iasc's maybe) that you have already manually loaded via
Preferences>Layout (1)>toolbar buttons, then you wouldn't instal the icon set supplied with the skin. MB would then default to those manually loaded icons.
If it wasn't to hard to do, you could even have a radio button option in
Preferences to "use skin specific icons" so you could change your mind even if you do have them loaded.