Hmmmmmmm.... Well it depends what you mean. Do you mean that Boromir had survived, but the orcs had captured Merry and Pippin and then Boromir would have just walked away? I don't believe that he would have tolerated the orcs to take them.
If you just mean that the situation (Boromir+Merry+Pippin against the orcs) hadn't happened, then I suppose you wouldn't be asking would he have gone after the orcs...
So could you clear it up a bit?
