I purposely presented the road names without regard to accuracy or comment in order to list what I believe AM has the artwork for.
As far as I'm aware, the list of railroads that had Pacific's with Vanderbilt tenders is short: B&O, C&O, Erie, GN, SP, TN&O(SP) and UP. New Haven may have done a tender swap on one or two Pacific's. You're definitely not going to find a Vandy anywhere on the Pennsy.
And of course, only the Erie had true USRA heavy Pacifics, (the Southern Railway PS4 was close, as were C&EI's...) so in a perfect world the model is inaccurate for any of the roads offered by AM, regardless of tender type.
But we're in S, so options for road-specific models are extremely limited. Some of the scale guys will get their tidy-whitey's in a knot over which road had/had not, but probably 95% of the 85% of the market won't.
As for myself, I'm being flexible. I'm thinking of the non-existent UP P-14 class Pacific and whether I have AM letter it or letter it myself is a decision I haven't made yet...
Rusty