nah they def will employ team orders in F3 and F2 if you're on teams like HWA and Prema.
Its very very rare, and like mentioned before its usually because they are in very different strategies and one of the drivers is way worse, they usually arent the driver that ends up in F1.
Russell for example probably never in his life had to move aside for a teammate until he got to F1* and on that Williams a few years ago, that matured him and he is coping with it much better at Mercedes with Hamilton, we will see what happens if the car stars winning more often.
*again not bc different strategies, but bc of purely for no reason other than to help the other guy have more points.