[quote=Dinh AaronMk]
From what I've been reading the Uzbek population never went above the single-digits.
[/quote]

Look at a map of Central Asia in the modern day, then look at the map of Central Asia in this RP.

Kazakhstan, as it's labelled in this RP, includes modern day Kazakhstan, Uzbekistan, Tajikistan and Kyrgyzstan. The only Central Asian country that's excluded is Turkmenistan, which apparently managed to find itself part of the Persian state somehow.