I'm only going to argue the points that I think are relevant, namely those economic ones. The discussion at hand is what urbanization and industrialization entail and how they happen, and why creating cities by fiat is unsustainable a priori. I think it could technically be done, for the record, but I also think it would destroy itself over time.
(an urban industrial process that could be supported by tariffs on imported manufactures ensuring domestic monopoly, or alternatively on cheap serf labour to undercut the costs of foreign equivalents through exports. Twould be a terrible system, but it would support the industry even if very inefficiently)
It's true that tariffs on imported manufactures help protect fledgeling industries, but they do not guarantee their fitness. You need export disciplines for that, or else the industries focus too inwardly - they don't export (too competitive) and only sell domestically (because tariffs give them a home-field advantage). In countries like Germany and Japan in the late 19th century, export discipline was not necessary to build a prosperous industry because Germany and Japan
both had rising middle classes as a consequence of their effective agricultural development, Prussia from having long since moved away from serfdom and ineffectual tenant farming and Japan from instituting land reforms. In other words, there was a domestic market for their goods that were not being exported all that vigorously.
In our hypothetical Russia where the farmers aren't moving to the cities because they're richer and want to invest their energy into urban endeavors, but are moving to cities because the Tsar told them to, that domestic market is absent. People don't have the money to buy manufactures, and that includes the farmers who might otherwise be spending their extra income on new machinery like tractors. As for big aristocratic landholders, it's worth mentioning that as a big landowner in a land of poor serfs, it always makes more sense to squeeze more money out of your agricultural workers than it does to invest in making the land more productive. And that includes buying tractors etc.
Basically, the industry is unsustainable.
Now even accepting your assumption that Russia was not at the theoretical agricultural threshold to support the development of an urban culture (and it is an assumption as I noted), the process of urbanisation simply shifts to the development of more efficient agriculture, with this then creating a population boom which facilitates urban development as people move away from overworked land. This would be a more natural civic development cycle that urbanisation by decree, but it does not preclude a deliberate urbanisation strategy making use of the population surplus.
Emphasis mine: this is not true. Urbanization does not mean more "efficient" agriculture, although it is often caused by more efficient agriculture. What I'm saying is just because you have cities doesn't mean you have more productive farms. Increasing the productivity of farms (yield per acre, not $$$ per acre, as these two almost never align) is achieved in two primary ways: small farmers with significant credit support to invest into the productivity of their land (or, as in the US, small farmers with no shortage of land to acquire),
or tenanted farmers, protected by the government from their renters, are incentivized to pull extra profit by investing in their land. By definition this precludes most peasant farming situations and
especially serfdom.
The point I'm making is that under an agricultural system that focuses on rent or serfs, labor is not being effectively utilized. This is what precludes the idea that Russia was sitting on a population surplus, much less a population that has money to spend on manufactures and wants to move into the city.
Now with regards to "realistic" in realistic urban development. I presume by this you mean a nice comfortable city.
Stop. No. I mean an urban development that can sustain itself economically and isn't held aloft by artificial inflations. When you neglect your agricultural development in favor of urban development, you crash and burn. See: Latin America, Philippines, Malaysia, Thailand, Indonesia. When you encourage your agricultural development first, you succeed.