Kurenai is a genjutsu specialist -- she works with illusions. I dunno, it doesn't make sense to have Asuma be only strong and good with taijutsu -- after all, Gai's already been established as the taijutsu specialist and with the 8 Celestial Gates, I don't think anybody could top him in close combat. Maybe Asuma's the balanced ninja. He's big and strong and good at all three: tai, nin and genjutsu, but superior in none, except for the previously mentioned fact of him being really big and strong.

Konohamaru doesn't have to be his son to be related, Asuma could be his uncle. Just a suggestion.