How is "Unrequited love" a part of the Taming of the Shrew?

Hortensio:

Sir, you say well, and well you do conceive,

And since you do profess to be a suitor,

You must, as we do, gratify this gentleman,

To whom we all rest generally beholding.

Tranio:

Sir, I shall not be slack; in sign whereof,

Please ye we may contrive this afternoon,

And quaff carouses to our mistress' health,

And do as adversaries do in law,

Strive mightily, but eat and drink as friends.

The above exchange would seem to imply that Tranio has unselfish motives and heroic deeds in mind, but he is anything but noble here. In this exchange, he likens a law case to the love triangle he's involved with for the opportunity to win the hand of Bianca. The men are compared to lawyers (their only interest in Bianca being professional); winning her hand is seen as nothing more than a competition; and Triano..... he's the odd man out.