Siberia was awesome, totally recommend.
Continue. West Siberian plain.
Before:
View attachment 504830
Red - state border, blue - redrawn rivers, turquoise - approximate position of swamps.
Overview:
Rivers are mostly correct, as I say. Fixes for them mostly supposed to place towns on the correct banks of them, and sometimes - to exaggerate their bends. Only suggestion — probably Tagil-Tura river (light blue) can be added as source of fresh water for cities of middle Ural (Tagil and Yekaterinburg).
Hills and mountains are ok - West Siberian plain is very flat, and we can just add some hills for Siberian Uvals east of Nizhnevartovsk. Or not, because they are rarely over 200 m height.
Most problem in West Siberia is incorrect placement of swamps - they are, firstly, located too far too the south, and, secondly, placed mostly in the banks of the rivers, blocking most of the historical city spots.
(Reference map for swamps)
Resources of the region mostly includes oil, furs and some food resources (deers in the north part, general food - in the south).
So, fixes
View attachment 504845
A. Added oil of West Siberian petroleum province; added deers for supporting northwest Siberian towns.
B. Added millet for enriching cities of Yekaterinburg and Tyumen.
C. Horses for Siberian Tatars and millet for Omsk
D. Sheeps moved 1N, added wheat and iron, representing iron ores of Bakcharskoye mine. I'm in doubt, though - while this deposit is valuable, it was found relatively late. Probably need to see Altay region as whole.