The node has nothing to do with size.
A chalice must have 4 parts: base, stem, node, and cup. That’s by definition. If it doesn’t have a node, it’s not a chalice.
Any chalice may be used as a “common cup” for the Blood of Christ, but a cup (w/o node) can’t be used as a chalice.
Usually, Church documents only speak of “chalices.”
“Common cups” are more of a marketing tool used by sacred-vessel manufacturers to allow for “sets” of vessels. One chalice, 4 common cups, and they all look like they belong together, is cheaper than buying 5 identical chalices, so a parish is more likely to spend the money on the whole set.
RS 105 says that it is “praiseworthy…to use a main chalice of larger dimensions” but this isn’t strictly-speaking required. (the word, after all, is praiseworthy and not required).
I can imagine some scenarios where there might be a good reason for using a main chalice that’s smaller than the others; especially if it’s more ornate, or has some specific spiritual or historic value. But this would have to be done in such a way that the other chalices do not detract from the main chalice as the focal-point.