That's why it's confusing. The unit they're showing marked "Mediterranean" is based on a Roman legionary from the Republic era, so I'm not sure where in the game this would appear.
Rome (and probably Greece) starts with a Warrior unit that looks very similar to this but is earlier and more generic. It's the version that is presented in the other slide about Age variation. This is then replaced by the Legion (and presumably the Hoplite for Greece). Note that the in-game version below has some more Roman shields, and presumably the Greek version will have more Greek-like round shields.
View attachment 706078
View attachment 706075
Now, maybe the shown figure is a per-figure variation for either the Warrior or the Legion unit.
Or maybe we might hope that the Republic legionary represents the Tier 2 Legion and the Imperial version represents the Tier 3 (unlikely). But either way it was kind of a confusing choice to show in that slide. I feel like whoever put these slides together didn't really have a good sense that people were going to be using them to try to learn specifics about the game.
edit: The only place I've seen where they're using the Republican version of the legionary is as some of the attendants for the Legatus in the accompanying clip on Army Commanders.
I finally got smart and went back to the etymological references.
In Greek, Phalanx meant "the battle array" - that is, the armed forces drawn up for battle. As it happened, in classical Greece that meant a bunch of Hoplites carrying spears and big round shields -
but that is not part of the meaning of the word.
In Latin, they borrowed the word unchanged from Greek: Phalanx.
BUT They changed the meaning, to "a compact body of heavily armed men."
Again, note: in the use of the word in neither language is any particular type of weapon specified.
So, I suggest that 'Phalanx' in Civ VII terms simply means all heavily-armed Melee Troops in Antiquity Age.
This would account for the fact that no 'phalanx' shown in any game shot so far has shown the majority with spears, or any figure with spears except the Greek hoplites or, in the one battle scene, what appear to be early Romans (and the Roman 'Legion' started as a decimal Phalanx of spearmen, 10 ranks deep)
Also, note that the early Republican Roman Legionary's weapons and armor were heavily influenced by other central Italian tribes (Samnites in particular, which even the Romans admit) and Etruscans, who were in turn influenced by the classical Greek hoplites. So, a 'Republican Roman' is not completely and solely Roman - especially since, before the Marian reforms, equipment was not provided by the Roman State, but by the troops themselves and so was bound to be somewhat non-uniform.
The figure shown looks 'early Roman', but could also be Samnite or late Etruscan - in game terms, then, Minor State or 'generic'.
This is still not entirely satisfactory: the most common type of mercenary soldier fighting in almost all armies from 350 BCE on was the Peltast, with javelins or a thrusting spear or a combination of the two plus possibly a sidearm of short sword or long knife and, very late, even a long sword. Later they formed a large percentage of Roman Auxiliary troops to the (Imperial) Legions, and at the end of the Empire the Legions were composed of infantry with the long thrusting spear, large round shield and long sword - and trained to use either spear or sword as needed.
