https://rheinmetall-defence.com/en/rheinmetall_defence/systems_and_products/index.php
EXRO's new strategic partner is described as a Tier 1 motor supplier for buses, trucks and off-road vehicles, with emphasis on the former. I have trouble seeing how Rheinmetall fits this bill. Maybe I am missing something.
Rheinmetall is primarily a defence OEM. Its list of products are included in the link. Mostly weapons, tactical vehicles and C4 systems. It has very little to do with commercial e-vehicles. And nothing mentioned about buses that I could find.
It does have two traction motors in its inventory. By the description in the product specs, these have only recently achieved validation and are unlikely to currently be installed in any vehicles.
I believe that Rheinmetall and GM Defence have a fighting chance with the Army's new Tactical Truck program with Rheinmetall's HX3 platform, which could be attractive for EXRO. As far as the new stategic partner goes, I would consider the more "pure" European Tier 1 powertrain providers such as Danfoss, Bosch, ZF, Vitesco, GKN and Borg Warner to be more likely candidtates, particularly the ones that fit the sales and employee description.