Isogamy in Mahabharata 5.33.98

[Sudalaimuthu Palaniappan]

In Van Buitenen's translation of Mahabharata, we find in the Viduraniti 
section (5.33.98)

"If he weds in his rank and not beneath him
Is friendly and deals and converses with equals,
And gives first place to the quality,
He is wise and his ways are well-conducted."

Given the instances of hypergamy seen in Mahabharata, has anybody commented 
on this?

Thanks in advance.

Regards
S. Palaniappan