Imho hydrogen on trains is only a good idea, for long distance trains running on not electrified track. Hydrogen is more energy dense and easier to refill then a battery so a good idea for say US freight trains.

However Germany has all its mainlines electrified. In this case all three towns have electrified main stations. Battery trains are a good solution for that relativly short sections of unelectrified track, as long as charging can be done in stations. This would be the case here, as in most of Europe to be honest.