I think that was supposed to mean 1 cup of greens. Raddichio and romaine are fine. You might also want to rotate in green or red leaf lettuce, endive, and chicory. A lot of the darker greens are high in calcium and can contribute to stones in your pig. The carrots have quite a bit of vitamin A and oxalic acid in them which combines with the calcium to create stones. Alfalfa is also quite high in calcium along with other nutrients, but it does not wear the teeth down the way a grass hay will. It's fine that they have it now, but they need unlimited grass hay (timothy, bluegrass, orchard, etc) constantly.
Based on your list, I would recommend no more than 1 grape tomato per pig daily, 1 baby carrot per pig daily, cut the grapes to a couple times a week (Fruit is really high in sugar, and pigs are susceptible to diabetes.), celery maybe 2-3 times per week (It has almost no nutrition that they need.), the lettuces the way you are already feeding them, and like daft suggested, add in some cilantro. I'm assuming the pepper strips you said are sweet bell peppers. They are an excellent source of vitamin C for your pigs, the red being the highest and can be fed daily, but you might want to limit them to 1 of the 2 feedings because they also have quite a bit of sugar.
You mentioned a dry pellet mix. What are you feeding? The pellets should be pellets ONLY, no seeds, nuts, or other bits. The extras are low in nutrition, high in fat, and pigs can easily choke on them.