The scale is sort of like the Campaign Series, but not exactly. If you compare it, say, to the Campaign Series: Middle East re-do, from Matrix/Slitherine, I feel the latter is much more purely tactical. At least, that’s the feel I get. The Panzer Battles games are sort of an in-between scale, but I like it. I do agree it has a bit more in common with tactical games than it does with the older Panzer Campaigns system.
As for AI, subjectively the AI in the Panzer Battles games feels better, but I am not the one to comment on that, as I suck.