Where is the evidence the Mongols took issue with this view? They certainly seemed to recognise the value of cities.
To my knowledge, the practice of falsely conflating intelligence and civilisation to be offended that not every society formed a civilisation is a modern occupation.
I think if you eat all neighbouring civilizations in a few decades, you're definitely a civilization.
If you run the cities, yes. If you only raid them, no.
(The Mongols built roads and founded a Chinese dynasty. They were a civilisation.)
Whether pastoralists are a 'civilization' (or even more fraught, 'civilized') seems like a completely arbitrary distinction to try to make, especially on the basis of something like 'cities'. The ability to organize, direct, coordinate, supply and project military power over great distances is a hallmark of plenty of things we think of as 'civilizations' and the Mongols were easily the world heavyweight champion of that, in their day. A great number of people found out the fact a stone wall is much harder to move than a yurt is not the tremendous civilizational advantage they thought it was.
Going back to the top comment: “Within the Silurian context, the urban distinction is almost demanding: if humans stopped at Neolithic pastoralism, there is a good chance all evidence of our tool use would have disappeared within a few millennia, let alone millions of years.”