I personally am not a fan of the railcars on the Arosa Line and want something more modern. And I think the best trains to add would be the new Capricorn railcars built by Stadler. Image Source: Railcolor News
IIRC the Capricorns are for Surselva and locals around Chur/Landquart - They can't haul wagons or additional coaches like the Locos or Allegras.
The Capricorns might run occasionally to Arosa, but they are not normally seen on that route. Better would be the Allegra.
I know the Allegras are used on the Arosa Line while the Capricorns are not. I just prefer the Capricorns to the Allegras. Or, they could add them both and it could be the "Arosalinie Stadler Pack"
The Capricorn doesn't run on the Arosa Line and never will. EMUs on the Arosa Line need to be able to haul freight cars, which the Capricorn can't. It was designed for the core network and will bring portion working to the RhB network, which is neither possible nor necessary on the Arosa Line.
