So as I tell you that both of them are illnesses that make people miserable with the potential to kill them, who have I damaged?
If I tell you that they're both deadly but one may very well be more deadly than the other, how is that dangerous?

I still don't see it.

Guns and hydrogen bombs can also be compared. They're both useful in destroying things and killing people. One potentially causes more devastation than the other, but they both could be used as weapons of war.

I remember in several English classes throughout my life being asked to "compare and contrast" various things. It's a common thing to do.