Well, here's the mod 5.5.
It contains a file called MMH55-Index.pak.
This file contains folders, and in the \GameMechanics\Creature\Creatures folder, there are folders with unit characteristics. Delete them, and the units in the cities will change.
In the same file, there is a MapObjects folder - it contains the heroes.
In general, I usually just open the mods and compare the contents of the folders, and that's how I find conflicting files.
Added 7 minutes later
Well, here's the mod 5.5.
It contains a file called MMH55-Index.pak.
This file contains folders, and in the \GameMechanics\Creature\Creatures folder, there are folders with unit characteristics. Delete them, and the units in the cities will change.
In the same file, there is a MapObjects folder - it contains the heroes.
In general, I usually just open the mods and compare the contents of the folders, and that's how I find conflicting files.