>>9386560HoloJP basically all live within a 1 hour train ride radius of each other, what with all being in Japan, and most of them living in the greater Tokyo area. Like you said, they can all go to the same office to do the big corpo group stuff, but the proximity has even more intangible benefits. They can easily offcollab, or just hang out on a whim, which is invaluable to build chemistry.
A lot of them already knew each other before from being in the same nico circles, another asset.
And being all japanese, they're culturally homogeneous, both in the general sense that they share the same customs and know what is expected of them/ how to play their role, and specifically how to commit to their character as an anime girl /idol, or they are at least familiar enough with it and it's not a "foreign concept" to them.
HoloEN is scattered all over the world, and even if they are on the same continent, america for example is huge. So offcollabs are a no go, they can only hang out over discord which is no substitute for the real thing. Timezones are another bitch, which further inhibits spontaneity.
Management seems extra retarded for this branch, being too much of a red tape.
Personality-wise, there are too many introverts/passive/wet blankets. Culturally they mesh less well, and the western individualistic background places less importance on forming groups. Anime and idol culture is more foreign to them and they have more difficulty committing to the character, more often they just treat it ironically and make it "cringe", basically just being a "streamer with an anime avatar".
NijiEN, while sharing some of the general problems, have some things going for them. Personality-wise there are less wet blankets, so the chemistry is much better, much quicker. They are not afraid to hop on each others streams spontaneously, and there seems to be less retarded management getting in the way of it.
I do still like the EN1s and watch them, but I feel nothing for EN2 so far and am rather watching NijiEN over them.