That's right -- but it does change the original problem statement.
Consider this solution:
Based on the original parameters, we really only have a limited number of factors to deal with. We've got a farm (yours), a bakery (mine), a farmer (you), a baker (me), and a child who consumes but does not produce. If we assume that we are both operating at 100% efficiency, then neither one of us has the option of increasing our output. You need two heads of lettuce and two loaves of bread every week, but you can only produce two heads of lettuce (which leaves none to trade for my bread).
The Marxist solution would be for you to assert your right to take one of my loaves of bread without compensating me for it, because you need it more than I do. You may be able to do this to me simply by overpowering me (if you are stronger), but I can assure you that I won't be baking two loaves of bread every week after this happens for the third time. This explains why Marxist states are always reduced to sh!t-holes by the time Marxism runs its course.
The real solution, of course, is that there is no way to meet all of our "needs" under these conditions, but we can make trade-offs in our individual situations that will allow us to allocate our resources in a manner that works out for both of us (hopefully) -- either now or in the future.
My suggestion is that we should both "settle for less" in the short term by making sacrifices for the longer term. Here's the deal: I will provide you with one of my loaves of bread every week (or every other week, or whatever we determine to be fair while keeping me from starving), and you will be permitted to keep both of your heads of lettuce. I will do this for a period of ten years, after which I will own your farm.
The social crusaders out there will call this "exploitation!" and complain about "all the wealth being held in the hands of a few people," but in our example it may work out well for both of us. We'll both make sacrifices in the short term, but we also both have a "goal" to aim for. My goal is to own your farm, at which point I will charge you some kind of rent for staying there (I can't evict you after the ten years, because I'll want your lettuce even after I own you farm -- especially if I haven't had any for ten years!). Your goal, on the other hand, is to trade off one of your major assets (your farm) in exchange for the ability to develop what may end up being an even more valuable (even in purely monetary terms!) asset -- your child.
I may own your farm after ten years, but at that point your child will be able to increase the output of the farm by helping you cultivate your lettuce. If you can produce three heads of lettuce per week with your child, then we've got another "imbalance" that now works in your favor. You can even defer the "payout" on your investment by refraining from having your child work on the farm after he turns ten -- and instead cultivate his interest in science, engineering, etc. By the time he's 20, he may end up with the ability to build that John Deere equipment that will allow you to harvest 200 heads of lettuce a week!