Again, if you want to make a suggestion format properly and run through the LAMP process. A curt one liner is not going to tell anyone anything about the proposal and more likely to antagonise. Besides DTG have pretty much ruled out doing American steam in TSW until they have improved the state of steam traction generally in the game.
ATSF #3751 (and also #2926, which was recently restored to operation) would be better suited for Cajon Pass. #3751 is kept in San Bernardino, by the way. SB is at the southern end of Cajon Pass. I really want ATSF #3751 in TSW4 for Cajon Pass, along with some excursion passenger cars, a P42DC Genesis, and a BNSF C44-9W. Maybe we could also get an ATSF FP45. All three diesel locos ran with #3751 on excursion trains in the 1990s and 2000s (plus, I want those locos in the game, too).