I think hydrogen fuel cell locomotives are the best trains that don't need overhead wire electrification. You can top them off in the time of a diesel (take that, BEVs), and can be turbocharged unlike BEVs (see Garrett Motion). While overhead wire pantograph electric trains are the best, I would put hydrogen fuel cells as the best behind overhead wire pantograph electric trains. Battery-electric trains are overrated, and I would put them at the bottom.