Incidentally, the Constitution of South Carolina has an anti-packing provision in it, that is of little relevance since Reynolds. New counties (which originally had one Senator each and at least one Representative in the General Assembly had to have at minimum one full Representative's worth of population and new county seats could be no closer than five miles to an existing one, thus preventing a city from breaking up into multiple counties.
Guam's population is far too small for Statehood, unless we are going to rewrite the Wyoming rule into the Guam Rule and more than quadruple the size of Congress. Congress arguably needs expanded in terms of the number of Representatives giving it hasn't increased in about a hundred years despite our population having vastly increased, but troubling or quadrupling is simply not feasible or desirable.
I think we may have discussed this exact topic before, but if the US could spend a century with Nevada having less than half the population of the next smallest state, we could also have Guam with less than half of the population of the next smallest state now.
If you add Guam + NMI (they have the same general culture, language, geographic proximity), you're above 200,000 people. If you extend the offer to the former US possessions in the region to make a state of Micronesia (something that would be a power move geopolitically considering their proximity to China), you could get above 500,000.