Ok, so I've got an idea for the story. Namely that one of the worlds that is seceeding from the Empire, Yecheng, cannot provide all of the necessary food to keep it going. It has relied on food imports from the other two worlds. It has some agriculture but not enough to sustain itself. It has a population of 300 million people. I looked up the average American daily food consumption and it's 4.7 pounds of food. Figuring that Yecheng can supply about half it's daily required food that would require moving about 350,000 tons of food to the planet per day. So I got to thinking, 350,000 tons really isn't all that much. Not when you consider that Voyager was said to have massed 700,000 tons. Heck, I even looked into it and by DITL stats a single Cardassian freighter could easily handle that much cargo in a shot, probably two days worth of food. Given their distance from one another you could probably set up a stable and sufficent food transportation network with about 10 ships.
So it's physically possible to move the food from point A to point B. Here's the real question, does it make any sense? As far as the story is concerned the Romulans don't have personal replicators as a matter of course, the cost in terms of energy to replicate food is higher than simply growing it and physically moving it. The Federation ships in orbit can replicate anything like that volume of food. Since the freighter captains are afraid to travel without escort it presents the problem of either escorting the freighters or trying to procure industrial replicators from the Fed that can replicate that quantity of food in the short term. Of course since the residents of Yecheng can supply half their own normal food intake does this really present a short term problem at all?