Generally when stuff is missing, it's because:
Not updated
or
Causing troubles
Feel free to try adding it yourself... personally, I've had zero issues.
http://forum.worldoftanks.ru/index.php?/topic/1654743-
(Scroll a bit down, one of the first two links, either Yandex Disk or Google Drive, is the mod)
Hehe, it happens
Do report back if you find any issues, and if you do find issues, attach logs - that'll help Aslain figure out if the current NA/EU modpack works fine on ASIA, even though you are missing the Holiday stuff currently.
You didn't rename the folders then (both of them, at least )
World of Tanks/mods/
World of Tanks/res_mods/
Both of those contain version folders, that need to be "0.9.21.0", if you want to try using the 0.9.21.0.1 modpack on it
It means you ignored the "Read mod description!" marker, and selected multiple skins that overlap/conflict
So go to the skins on the list, and uncheck some of them.
Would give you a better list, but you forgot to attach log files
You selected multiple skins for the same tank, please read the notice on the things you selected.
It clearly says "[read mod description!]"
For example skins you picked:
Begleitpanzer 57 Remodel (Milkym4n)
T-64A (Milkym4n) [read mod description!]
T-90A (Milkym4n) [read mod description!]
T-54AM Remodel (Milkym4n) [read mod description!]
You would need to logout, and then login with the other account, activate/and what not, and then login to the game afterwards.
I don't think you can easily switch any other way... but maybe someone else knows better