The exact Egyptian wording of the title.

The so-called Hittites never referred to themselves with the Canaanite name ‘Hittites’ and to their language as ‘Hittite’; their real name was Nesa and their language is by extension properly referred to in English as Nesite – the names ‘Hittites’ and ‘Hittite’ are just an unwieldy historiographical convention. The tribal group that actually bore a name close to ‘Hittites’ – the Hattians – were completely unrelated to the later Nesites, but when the Nesites became the dominant group in the land of the Hattians, the toponym ‘Hatti’ for the area remained, which is where the confusion comes from. The game differentiates between ‘Hittite’ and ‘Hattusan’; the former in real life was ‘Hattusan’ and the latter ‘Nesite’, which is exactly how the mod renames them.
Breakdown of our knowledge of the area back in the day:
Historical sources contemporaneous with the events of the game do not mention Phrygians; a kingdom or perhaps even a whole tribal group called Kalasma is mentioned to the northwest of Hattusa, while to the west, a cult centre called Istanuwa is referred to. Both were culturally and linguistically Hittite. Archaeology reveals a complete cultural overhaul of the region around 1200 BC, supporting the idea that Late Bronze Age Hittites of pre-Phrygian Sahiriyan basin were replaced by a foreign population.
Homer on the other hand refers to ‘Phrygians’ as though they were an established nation before the Trojan War already, which is roughly when the game begins.
Later Greek authors also refer to a tribe or tribal group called the Bryges, with an unclear relation to Phrygians – they may have crossed over into Phrygia in order to become Phrygians, but they could also be unrelated to Phrygians altogether.
The devs, apparently confused by the seemingly conflicting sources, decided to go partly with the mythical Greek version, portraying the local cultural centre as a Phrygian ‘Gordion’ (which is not the Phrygian name by the way) inhabited by Phrygians, while also throwing the more historically plausible Phrygian Invaders into the same campaign.
Having to adapt to Sofia’s decision to depict all of this area’s dwellers as a separate cultural group, I have decided to simply marry all the versions, depicting the region as occupied by nascent Homeric Phrygian states, but with pre-Phrygian toponymy, and Phrygian Invaders representing the Bryges that have not yet settled.
The polity Manyan Phrygia, just like its Luigi Ascanian Phrygia, is literally 100% made-up, or to word it more beautifully conjectural, and is not mentioned in any source whatsoever. At the same time, the country Kalasma, which was potentially not a single state but rather an entire cultural group related to but not identical with the Hittites, is missing, as is the tribe Bebryces that is attested in the area as part of a Thracian or Phrygian migration into collapsing Hattusa. The unclear ethnic affiliation of the Bebryces and the similar name allows their inclusion into the Phrygian cultural group, while the local toponymy is left as referring to Kalasma and sites associated with that realm.

More or less same thing but in Egyptian (literally: ‘walkers-[on-]sand’).