shaglio
The Prince of Dorkness
Light Cavalry is a unit type - not a specific unit. There are Light and Heavy Cavalry. While technically we don't know which type the horsemen is, I think it's a fair guess that it is a Light Cavalry unit considering the fairly specific name of the Heavy Chariot.
The real question is what the Knight and Later Cavalry unit classify as. My guess is that the Knight is Heavy, and the Cavalry unit is Light. So it's possible that Scythia won't be able to spam knights.
I'm a dummy. I meant Heavy Chariot, not Light Cavalry Just do a mental Find/Replace, I guess.
EDIT: I didn't realize my little slip up would cause such a commotion. I'll have to watch the video again when I get home from work, but I thought the narrator specifically mentioned only the Saka Horse Archer and Heavy Chariot as eligible for the 2-for-1 deal.