Your Asian players will always be faster and higher because they run multi-boxed accounts. You can put money that those toons have been online %99.999 if the server is up.
I use to play quite a bit Asian MMO's... Lineage is known for being one of the hardest games to level in of all MMO's. When the game first came out it took a Korean account around 3 years to reach max level of 80. When they hit it the "owner" of the account was interviewed and they flat out said the account was ran by at least 3 players.
This is how they'll run all accounts. Now, the sad part is that in many cases they'll be multi-boxing more than one character. So, one player could be running 2-4 toons all by themselves.
Imagine running an entire 4-man Greater Rift by yourself and you'll get the idea.
I applaud them for their dedication and ability to share work/reward. Though it'll always bug me a little that rarely will a US player ever be "Top Dog" in any game, no matter what region or server they play on.
To be fair, "Asian" is quite a generalization and to call it multiboxing may be premature. China is much more prone to this, but if it were a Korean I know they dedicate 15-18 hrs plus a day in league or StarCraft so I could see this being legit. But, alas I cannot say this to be true.
I used to be that kind of gamer when I played WoW. The first day of a new arena season I had enough honor banked for belt, bracers, rings, neck, boots etc. You only needed Conquest points for the season set and weapons during TBC. I would actually PVP 18 hours a day through a weekend to be at the top of the curve the first day of a season.
The thing about D3 that I don't get about these kinds of players is what's the advantage? If competing against people for top solo or 2, 3, 4 man GR's I get it but honestly I don't get the same sense of competition for that as there was for a top arena ranking from WoW.
So much of this game is 100% RNG that I don't see the advantage of pushing that amount of paragons ASAP. You may still not have a good Compass Rose, COE, Slanderer/Little Rogue etc. I'm pushing 600 points and I think my characters sucks because of bad RNG. Having 1200+ at this point would make me, potentially, even more frustrated.