For most factions it's straightforward, if it looks like a lump of clay, it's old sculpt, if it has right angles, it's CAD. With the Aleph range I'm a bit confused. The vedic range is obviously old, but the Greeks also doesn't look like the new CAD minis. I suppose the Thorakitai box and the Garuda blister on top of CB webstore are new sculpts. As far as I know, Aleph came out with N2 Human sphere and the Greeks came with Paradiso.
I'm going to start by disagreeing with your assessment of model quality. But looking in the catalogue, I'd say it's everything since maybe alternate Penthesilea or thereabouts. I don't have the models in hand, but that's my best guess.
Most notable diverence is the size of the models and the connection of the joints. Best is to look up the date of the switch and look up in the catalogue from there. I’d say that the details aren’t as smal on the digitally sculpted models, but I can’t say that for sure for the hummies.
Whilst Steel Phallus came out with Paradiso several of their troops existed beforehand. Myrmidongs, their officer, Achilles V1, and Patty are all pre-Paradiso
I've circled all the ones in red that are CAD, but I might be wrong about Teucer. Actually, pretty sure I am at this point.
Yup, it was one of Fausto's earliest infantry sculpts (along with the Anaconda pilot and the lady ABH sniper/biker) you can see the renders on the GT Studio Creations Facebook page.
There was also a transitional period where there was a mix of digital and traditional sculpting depending on which artist did which model.
Even the same artist, Jose Luis Roig retrained himself to sculpt in CAD whilst still sculpting traditionally.