"Menos Grande" in my calculations specifically refers to the standard, mindless sort of Gillian, for precisely the reason that they work differently than other Menos. (Or rather, other Menos work differently than them.) Non-sentient standard Gillians indeed
are a specific class between base Hollows and other Menos for exactly the reason you mentioned.
As for width of Rukon rings, (each ring is then divided to four actual districts based on cardinal direction, remember), I initially assumed them to be 2 km wide, but that seemed too small compared to size of Seireitei itself - unlike Rukon districts, we have a fairly good account on how big Seireitei is supposed to be, and it is
huge.
I then concluded each ring would more likely be comparable to a town or county by itself, based on how much wilderness even districts closes to Seireitei have. Now, what mental image "town" or "county" invokes for you probably depends where you live - I live in Finland, where counties are loosely populated and pretty big. My own home county is 40 to 50 kilometers across, depending on which way you're crossing. My actual home town is easily 5 kilometers wide, and its infrastructure resembles Rukongai in looseness of construction. Distance to the nearest other proper town is 10 to 50 kilometers, depending on which way you go.
Mind you, even with the diminutive assumption of 2 km width per ring, Rukongai + Seireitei still ends up 615 kilometers in diameter, meaning 296,909.625 square kilometers. That is
still the size of a respectable country. (Slightly smaller than Finland, actually. Finland's area is 338,424 square kilometers.)
Bleach high-speed movement is not teleportation. It is high-speed movement. I hate it when people don't understand the difference, especially when it has been a
plot point that some persons can or can't follow someone's movements during Shunpo/Sonido/Hirenkyaku etc.
The only case of actual teleportation have been when Tessai used forbidden time-space Kido Jinkanteishi, spells used by Hachigen to dispose of several Gillians and Barragan Louisebarn and when Sousuke Aizen rematerialized around the Hogyoku.
By the way, Bleach high-speed movement is not particularly fast. Most feats of high speed shown in the manga would be possible at speeds between 100 to 200 kilometers per hour. What is fantastic about Bleach movement is not speed, but the fact its users can turn on a dime and react much faster than any real human.
To understand what I mean: takes this
reaction time test.
I got 240 milliseconds, or bit less than fourth of a second. Now realize that an object moving at 100 km/h moves roughly 28 meters in a second. One fourth of that is 7 meters.
That is fast enough to run across the room I'm in, around me and stab me in the back before I can react. Which is perfectly consistent of how high-speed movement is displayed in Bleach. It's even pretty consistent with the distances they are shown traveling on screen.
There are only few oddball cases where it isn't, such as Molting Cicada or Gemelos Sonido, but those feats would be impossible to replicate with speed alone, and are, indeed, likened to magic tricks, suggesting a visual illusion is involved.