And to a point to show you how little streamlining you can get away with: the Siemens ES64. OBB uses these at 230km/h on the regular, and the max anyone has had one topped out was at 357km/h.
I bet that Siemens weren't mucking around with what aerodynamic engineering they did do on it.
I'm no expert, but I do see a number of key features there:
1. Sloped front rather than pointed front, should be good for displacing air upwards rather than laterally.
2. Looks like very deliberate curvature on the piece of fairing between the front/top and side, I bet that is the result of high performance CFD modelling.
3. Good exploitation of the boundary layer effect on the sides, with the piece behind the buffer there to push the air well clear of all the messy mechanical components that can't be fully faired in.
4. Side fairing comes down quite low.
5. Protrusions from the side of the body are minimised, even the handrails for the doors are partially recessed.
6. Windscreen wipers mounted on a rail, keeping the airflow over the front nice and clean.
And all that while keeping a largely conventional body configuration instead of creating a streamline body that would be a pain in the rear end to work with on a day to day basis - though with it being Siemens you can also bet that the electrics are reliable enough that day to day access is not necessary.