I'm in n' out of PHX (Sky Harbor) every few weeks. Don't know what this train thing is, but they don't go to the rental facility. Thats served by busses that drive through the airport literally every few seconds.
I wouldn't be worried about height at all, but pulling that monster over, or even finding a curb long enough is another issue. There is no possible way I would take your rig to the inside drop-off lanes, leaving you to compete with all the commercial traffic, and those guys are worse than taxi drivers.
IMO- Park offsite and take the toad.
