Sweater- more sts in front or back?

I’m making a nice lace sweater, and am well on my way working the back piece, and its a touch too big. The front and back are identical in this pattern (up to the shoulders). If I wanted to make my next piece smaller by an inch or two, do I make the front or the back piece as the one with fewer stitches? Does it matter if the potential wearer of this sweater is busty?
Thank you!!

You could have the larger piece be in front; if it were in back it would bunch up more under the arms.