They were one of the wealthiest countries and quite industrialised in this TL
Which is where the wanking comes in. Russia was a damn backwards place compared to the rest of Europe at the start of the period this TL runs in, and OTL , while there were some improvements, it remained backwards. In spite of a formidable growth in population it was weaker with respect to the other major European powers at the end of the 19th century than it was at the beginning. Urbanization was low, literacy very low, and most of the population were terribly poor peasants (more than half in medieval bondage until the 1860s) which produced low surpluses and tended to starve in bad harvest years due to the government's desire to raise revenue selling Russian grain abroad regardless of whether it was needed at home. It was misgoverned by the Romanovs, who with a few important exceptions were arrogant fools who couldn't find their asses with both hands, a written guide, and a set of tailor's mirrors. Russia was finally experiencing an industrial boom in the years leading up to WWI, but was still on the average very backwards, and in a one-on-one war vs Germany in 1914 would have been eventually ground into chutney.
(This could certainly have gone differently, but doing much better would require some pretty major changes. Whether they follow logically from the POD, I dunno: I'm not going to reread the whole TL to analyze the issue.
)
In our post-USSR world there's a tendency to romanticize the empire of the Czars, but really, it was a badly mismanaged country with huge structural problems to overcome, and in turning it into the greatest military power in the time frame of OTL WWI is, indeed, a wank. (Not as big a wank as the Argentina-wank involved in the development of the UPSA
, but a wank nonetheless.)
They likely have the greatest population in the world
Unless there's been a population boom well beyond the already impressive growth of OTL, this Russia, which directly rules less territory than OTL Russia (well, aside from Russian America, and that's hardly Sichuan), has probably less than a third the population of China.