More goof-ups... One says the PT's rare, one says it was successful and common.
Classic SW EU!
What I see there, and I'm disregarding the AT-AP Databank entry all-together at this point (Whoever wrote that is clueless I think), is that the AT-PT was "rare" compared to the RT... It doesn't come out and say it, but that implies to me the RT's been in service longer, and still being utilized due to speed issues. The PT could just become popular and "flourish" then as time wears on because anti-infantry support for troops is a growing concern for the Empire...
The AT-XT from the CW game DOES, basically, show up in EU over time... There's like a 1000 (I'm exagerrating, but not by a lot, haha) different 2-legged styled Walkers throughout Comics, Games, etc... I know that Tech Commentaries does a half-assed job of categorizing them as best they can, and some do look like the XT... They could all just be a large variety of "armor" in the walker class that see service both public and private across the galaxy for long periods of time...
That Databank entry for the AT-AP/AT-PT is terrible... First, the AT-AP is F'n big. It's not a light anti-infantry weapon, it's not even on 2 legs, it sports a number of weapons including one big-ass gun... Hell it looks like the front end of an AT-TE really.
I don't see a correlation between the AT-PT and AP besides them being "walkers" really.
To me, the AT-AP doesn't even remind me of anything in the OT, nor even EU really... It's its own thing as I see it right now. It's cool though... A 3-legged walker, fair-sized (larger than a Scout Walker by a bit, and it seems to pack a bigger punch too) was a nice deviation from what we were used to... So's the Juggernaught for that matter.
The EU that highlights the AT-PT's use in the Empire was a couple games at least... In the Rogue Squadron games, AT-PT's act in support of larger armor to snuff out Rebel infantry which pose a substantial threat to the larger walkers (IE: Luke's ability to trash an AT-AT himself). Some RPG stuff's elaborated on it as well, and then the Force Commander game also showed them in use extensively for perimeter defense, probing enemy emplacements, scout/patrol work, and simple staggered defenses utilizing armor.
I've come to just sorta ignore Zahn's comments ont he AT-PT other than the Katana Fleet had some on board the Dreadnaughts for planetary invasion work or whatever...
The AT-PT's become one of my fav EU vehicles I think. I'd kill for a Hasbro AT-PT, especially after the RT turned out to be such a nice toy (the walking feature blows, but it's got poseable legs and all, so they did it justice).