Yep, because Law put much more into it. You know there is a difference in strength of DF attacks as well, right?
Law literally cut the mountain with the attack vs Vergo, meanwhile the one Smoker stopped was Law trying to cut a beaten Tashigi.
To deduce anything from that is nonsense.
It really wasn´t, see later Vergo demolishing Smoker with his Haki.
Law was not hurt whatsover, and was a few minutes.