Of the generic rule sets for Ancient Warfare, I agree that Armati II are great. Much overlooked, and deserve better.
My personal view is that most generic sets like DBx, Armati, Impetus even AMW etc were all originally written around the Classical period for Greece/Macedon/Rome and then expenaded outwards. They often give a good simulation for things like Successor battles, but otherwise there’s a bit of “Eh? What?” when you use them for others. They may work as a game, but I’m not sure they’re a great simulation.
That’s why if I’m doing anything other than Classical Battles I prefer to tailor my rules to the period, and that’s also why I wrote a specific set for Sumerian Warfare and published them: https://wargaming4grownups.blogspot.com/p/wargaming-for-grownups-rules.html