I apologize for the late reply.
When I first read “why the west rules for now”, and “the measure of civilization” I was thinking the same thing: That there is no nomad paradox, as you said, nomads are incredibly wealthy when compared to settled pre industrial peoples.
Similarly all that moving around, produces and transmits a constant stream of information about prices, environmental conditions, social situations, risk calculations, etc.
The only thing left unexplained is the largest settlement part, but one can very well argue the size of the largest settlement, is but a proxy for the logistic capacity of a given society. Largest gathering would probably be a more general measure, or alternatively largest gathering lasting over a certain time threshold. That way we could include the moving of a quarter million men, their horses, equipment, and so on during a campaign.
One could also argue that Nomads don’t exist by themselves, and nomadic empires evolve along with urban centers.

As for the output calculations.
According to Smil’s energy and civilization a horse can produce 11Mj of work a day, which is about 127W. Smil also suggests pastoralist society would require, at a minimum, 2.5 horses (or camels) per capita. When adding the requirements for cooking and food, we will be dealing with about 517W per person. It should actually be a little more than that, for we are not counting the energy needed to produce the commodities used.

So Pastoralists 517W at a minimum

Ian Morris seems to count the man hours of labor that went into the manufacture of a given commodity. So a complete estimate would involve the fashioning of an average basket of goods a society consumes, and the amount of energy required to produce each one, including human labor. If we are wiggling to assume urban dwellers do not participate in the production of food, or if they do it is to the same extent that rural dwellers participate in the manufacture of commodities.
Then:
Total energy used = the caloric consumption, + (percentage of urban population)*constant relating human work output + other sources of energy.
As to be fair to settled cultures, let’s grab the Netherlands just on the eve of industrialization, also because most of the information we need seems to be neatly arranged in Jan de Vries’s “first modern economy”:

Total energy used = the caloric consumption, + (percentage of urban population)*constant relating human work output + Energy employed in shipping/population + windmills/population + other stuff.

For caloric consumption we use the same base value as in the OP, 200w

42% of its population is urban in 1750. (Page 83 Vries’s “first modern economy”) Keep in mind the Netherlands is an outlying case. Around this same period England has about 16% of urban population. Going back to Smil, a person can deliver 2Mj of useful work per day, which comes to 23W. 42% of this is 9.7W

A term for wind transport (page 462 Vries’s “first modern economy”) a maximum of 700 million ton-miles of shipping, representing about 40% of Europe’s shipping, this is again an uncommonly high number for a settled society. 700 million *1000(kg per ton) * 1852(meters in a nautical mile)/ (365*24*3600*2.1 million (Dutchmen)). It comes to about 10.54W

Let’s add a term for the Windmills, Smil, reports a “Typical windmill” to produce 7.5KW. There were 12000 of them in 1800, 7.5*1000*12000/1.951million or 90/1.95, 46W. This seems a bit high in light of everything else, but I couldn’t find reliable numbers for 1750.

So we have 200 + 9.7+10.5+46= 266.35 W
We can round it to 270 W to account for the energy employed in manufacturing steel. Still slightly over half of what a pastoralist needs to be ecologically viable.