Question about radios

[Imp]

Okay I did not really understand that & have no need to know where the units are.
Mobhack stated

Contact is in relation to your superior in the command net.

So B1 + B2 can contact superiors buy radio.
B0 can also contact his superior AO & in fact is near by as has voice contact

As said before though the only ones you need to worry about are Red ones out of contact the rest look after themselves the games figured it out obviosly if you can contact your superior he can contact you.

I rarely use HQ screen for contact apart from maybe to check radio availability at start if its an early period game.
The units contact details show when you select it at the bottom of the screen & while not a hard & fast rule if you use move platoon leaders last they gets in less trouble so can rally others & can be moved to bring the others back into contact if need to.
If you have the CD & press the 5 key it even highlights who he is in charge of for you saving you many hours of game time if you play often.