I'm sure we'll know more on the 29th, but here's my guess:
I've allowed myself to adopt your great overview slightly:
Melee: Warrior ------ Swordsman ------ Musketmen ------- Infantry ------- Mechanized Inf.
Anti Cav: ----- Spearmen ------- Pikemen ------- Bazooka ------ AT Trooper -----------
Ranged: Slinger - Archer ------ Crossbow ------ Field Cannon ------ Machine Gun --------
Siege: -----------------Catapult ------ Bombard ------------ Artillery ----------- Missile Artillery
Light Cav: ---------- Horseman ---------- Cavalry ----------- Helicopter ------------
Heavy Cav: Chariot ------------ Knight --------------- Tank -------------- Modern Armor
Recon Scout ------------------------------------- Ranger ------------------------------------
Melee Ship: Galley ---------- Caravel ----------- Ironclad ----------- Destroyer ------------
Ranged Ship: -------- Quadreme--------Frigate ----------Battleship -------------- Missile Cruiser
Covert Ship: -------------------------Privateer ------------- Sub --------------Nuclear Sub
Fighter Aircraft: --------------------------------------------- Biplane ---Fighter ----Jet
Bomber Aircraft: --------------------------------------------------Bomber ---- Stealth Bomber
After thinking a bit about it, I do like the system quite a bit. A few thoughts:
Knight -> Tank might seem like a huge gap when we imagine knights as medieval knights. But Cuirassiers were quite similar in their role and even looked similar. The knights (heavy cav) were the first to use pistols, quite some time before light cav with carbines (dragoons/wild west style cav) started to dominate. Cuirassiers were used until mid-19th century, light cav until motorized vehicles became common enough to fully replace them (WW2). Example for a cuirassier demonstarting the fluent shift (around 1630):
Sure, this could be seen as a different unit and may have been worth to seperate, but imagining lategame leftover knights as cuirassiers might help immersion.
The new solution also allows to understand what actually happened: Cavalry became more and more useless due to better firearms, but both tradition and lack of alternatives forced nations to still field them - as outdated as they were.
Another important thing: While promotions carry over through the ages, ressource requirements change!
Spearmen might be the backbone of your army early on due to being resourceless, but this doesn't mean that resource-poor nations field tons of bazookas later on (as infantry is most likely resourceless, so the melee line will become more dominant).
Also, I'm pretty sure that strategic ressources are no longer counted on a per-unit basis. This essentially means that any nation having one or two iron/saltpeter sources might field unlimited numbers of swordmen/musketmen (see
this post/thread for more info)