“Show all” is a generally dangerous feature, since there can be varying amounts of things being shown. Without some limit in some form, it would be very easy to destroy database performance in the perfect storm of a few people requesting ‘all’ of something at the same time.
Overall, though, these lists are difficult to work. The first two are relevant for me, and after that it’s just a collection of stuff that I’ll never join up into the largest territory (states away, or across the country). I could see it being very difficult to navigate a situation where there are ~a dozen nearby territories that could be joined up with some effort … There’s definitely some work to do around making these more identifiable, or more easily viewed in a safe way.
It sounds like Replace England's admin level 6 (and 8 in some cases) with admin level 10 might be relevant in your area. It’s been very difficult to get consensus on some of these areas - some find the larger areas too big, some find the smaller areas too small. More opinions in that thread would be helpful.