In bridge, if you overcall two clubs over an opening one spade, you haven't taken up much bidding space, because your overcall hasn't kept your opponents out of any suits, only one NT.
If you overcall two clubs over one diamond, you've done quite a bit more damage, because you have prevent your opponents from bidding a major (or no trump) at the one level.
Does it therefore follow that you can overcall two clubs with a slightly weaker hand over one diamond than a one spade bid because the "disruption" to the opponents is significantly greater?
That is, assuming all other things being equal, like vulnerability and part scores. Perhaps the type of game might make a difference in the answers.