To me, it seems that team A has a scarce amount of keepers as it is, so this might actually be worth it for him to make this trade. As such, I definitely do not think the trade is worth vetoing.
Not to mention that, as the first poster said, a trade should usually be quite lopsided for a commish to veto it; its a bit different when the league members are voting on the veto, but you have to be careful not to extend the "long arm of the law" too far in the course of trying to keep the league fair; that's how you lose league members.
Take a look at my proposed scoring system?
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