Ideas, suggestions and feedback on unit behaviour & balancing

[Locarnus]

Units and unit behaviour is one of the core components of PzC modding.
Thus after ~10 years of PzC modding I'm very interested in the different approaches and experiments concerning units and unit stats.

For example I remember reading somewhere that guille1434 prefers to have two modes for recon units. A "tank" mode with 2 range spotting? And a "recon" mode with 3 ranges spotting and +1? defense, but the recon unit can not attack. It was something like that, if I remember correctly.

Or aircraft in Battlefield Europe mod being able to switch to a "long range ferry mode", so that they can be redeployed between the theaters.
Or 3 switchable modes for submarines: "Surface" mode, "periscope" depth, and deep dive.

I'm tinkering around with the rate of fire stat in particular, for balancing purposes. Eg to nerf early T-34s offensive capabilities, adjusting for their bad historical ergonomics (cramped 2 person turrets, bad optics and field of view and such).

What special or noteworthy unit behaviour or balancing approaches did you come across? What did you like, what would you wish for?