I didn't mean it diluted the original cards (though it does to), I mean the expansions dilute each other.
One older example would likely be reckless but in this case for instance one skill cards ability was that it let you cancel out all other skill check abilities. That card is of course more powerful the more skill check cards you have in the decks. (Though maybe it would only be used with IC anyway.)
Restore Order has to be played before the check, so Investigative Committee doesn't really have an interaction.