I would very vehemently disagree.
1. There is a pogrom escalation. Some types of pogroms do not appear until time has passed, and some yet other types do not appear until you join the Mutant Alliance.
2. The 'freelance' pogroms that are within the scope of the discussion here vary in difficulty dignificantly.
Right from the start in January, three types of pogroms can spawn: Bandits(Ratmen, ghouls, bloodoges, cars), Ku-Klux-Klan(White Hoods+ Police) and Humanist Supremacists (Brownshirts, Instructors and a Leader).
Of those three, the Bandit one is SIGNIFICANTLY more difficult, but is not an escalation, since it can appear from the start.
In later months, other factions may appear (Spartans starting in March, Deep Ones starting...sometime). The first three never go away.
As far as difficulty goes, I would say that the spartan one is not super difficult(grenade spam notwithstanding).