Okay, for my deadliest expert pool, this Highland Games Champion, Francis Brebner is in with the Spartan and the Aztec boxer. Big fookers like him and the small size of horses of the Bronze Age and early Iron Age are the reason why you had chariots in the first place, because he’d squash the horses of the day. Seriously, the primary reason for the chariot in Europe was as a battle taxi. In Asia it was as a firing platform. The scythes were a later innovation, used for the last time against Roman forces in Asia Minor at about 100 B.C.
As for the immortals, they were the only professional infantry in Asia other than Greek mercenaries. They were interestingly armed with bows and counter-weighted golden apple spears and a short stabbing sword, not the axe depicted. They did not ride chariots but were all purpose troops, light spear men and heavy archers. The Spartans cut through them like butter. They were considered to be the strongest Persian men. However, when Polydamas [Many-Subduer], travelled to Persia at the request of the King of Kings, he was pitted against three immortals in an unarmed fight. As a giant, who actually killed a lion with a war club in imitation of Herakles and had won the pankration at Elis, he killed all three men with his hands.
As for the Celts, outside of their modern range, the province of Galacia in Poland, and of Galacia in Turkey, and of Galatia in Spain, are a reminder of how far flung their migratory conquests once were. In the mid 200s B.C. they successfully invaded Greece.
The celtic sword is nicely balanced for slashing but did have a rounded point. Against an immortal with a wicker shield I would recommend using the edge of the iron shield to drive downward at the chin, clearing the highline for a neck lash. If the Persian armor must be defeated a hard-pivoting upward thrust is best against scale armor, and the wicker shield is not as much of a sword hand threat as the harder shields. Unfortunately, shield mechanics seem to be lacking in this group of experts.
I love the Burda club. I want one. Ash is a very nice ballistic wood. I fought about 20 bouts with ash wood batons and found they held up as well as white oak, roughly ten times more durable than red oak or pine. Ash was the preferred wood for ancient Hellenic spears, and the spear was their primary weapon, not something they wanted snapping early in the battle.
The scythed chariot was not a weapon used by the infantry, but a special corps of killer vehicles designed by Darius II [180 years later]in desperation to find an answer for Alexander’s unstoppable army, and the weapon system was so rigid that it required prepared terrain and was easily defeated via maneuver. The reason why the chariot was used as a firing platform and battle taxi was that the propulsion system was in the front. If you kill one horse the whole thing stops. Even so, functional chariot forces [of which scythed chariots were not one] were defeated by light infantry. It was found that men armed with light hand weapons could run alongside chariots and get into them, murdering the driver.
A Well of Heroes