Furthermore, the Old Irish carpat (ˈkaɾ.bəd̪) for chariot can only be derived from a Celtic language. A borrowing from Latin would have resulted in a completely different form and pronunciation.

The game's fundamentals have definitely been altered. It's easy to build branches that can then bypass defenses and reach the Civic Center. In theory they should hold up, but not that much armor.

If it's like a pirate society but on land, some groups are just as aggressive as a wasps' nest, while others are simply aggressive.  But these are societies that can easily create an army. I remember reading about the Gallo-Romans; having many Celts in their composition meant they could have levy militia troops, and this was true even in the Middle Ages.

No I don't think so. Pomponius Mela is the first to mention this implausible description but he was a notorious armchair geographer. Later on, several poets mentioned the scythed chariots but they were fabricating things. Thus, no scythed chariot. The reliable primary sources do not mention scythed chariots.

I don't know if it's an RTS, but it looks interesting and cool.