My Cute Wife is Mitsuri Kanroji

I was researching more about Hamon, and I came across a question.

Hamon generates energy that is identical to the sun's energy, which can be used to fight undead beings.

But does Hamon also strengthen human traits, like Breathing Styles do?

After all, if it doesn't, then how could Jonathan and Joseph fight vampires and Pillar Men with such high abilities while still being human? Those monsters should be able to kill them before they can even generate Hamon, right?

So, am I correct in thinking that Hamon also strengthens human traits? Anyone with knowledge about it, please give me some blessings.