Um.
Railroads have power on run through agreements all the time. Plus companies lease power to each other, or lend units to pay back for power used from another company. Plus there are power pools for specific service where the locomtives stay on the train for it's full run, even after it leaves home rails.
Add to that that KCS has all its new units painted at Coast Engine & Equipment (CEECO) in Tacoma, WA on BNSF.