Also, they had mayors and stuff, a VERY clear class division and were technically under the rule of Gondor after the Northern Kingdom fell but Gondor didn't really have the resources or urge to do any ruling over there. Once Aragorn was in they were essentially an autonomous zone under military protection in exchange for maintaining the local roads and bridges.
on the plus side like 85% of the book is set in Umbar, and it's a pretty cool characterization of the city
I like how it turns some life into the Middle Earth because originals really portray it as the mostly uninhabited wilderness, and both the numbers of troops at Pellenor and the analytic works like Atlas of Middle-Earth support this initial feeling.
I remember also one other Russian writer, Nick Perumov, wrote a trilogy placed in the 4th era, which present way less dreary and boring picture than official endings are suggesting. Worth the read.
do you have any idea if his books are translated somewhere?
No idea about English. They were translated to Polish, but it was long ago and didn't see any of them for years.