Yeh, he smashed Stephens, but again, that isn't saying much. Stephens is a very basic striker with a limited moveset who mostly just relies on power. Stephens made him look good.
You can see improvement for sure regardless of comp, but in Yair's case it doesn't really seem to be anything remarkable.
How do you put him above the others in the division? Max beat him in the striking easily, KZ was a better striker despite losing.
Being wild and dangerous doesn't mean he's a good striker. If it did, well then Volk is clearly one of the worst strikers in the division. Being effective is what matters, which is what Volk excels at.