Assuming at least 10 teams in the league, as a current commish, I would NOT veto the trade. Especially if your trading partner has a hole at SS.
You get the better end for sure, but there seems to be a common misconception about equal value, and fairness.
Clearly, Albert Pujols and Haren for Tulo, would be unfair. However, I would say this deal is fair, though your side is the obvious benefactor.