Cross-attachment question

[matxer]

In the manual (yes, I read from cover to cover - pdf-ly speaking -, but even after several years of practice, I still don't understand everything, I must be a slow learner), it is recommended to cross-attach units so that they have a company leader (in addition to the platoon leader and the HQ).

Good to know, but what are the criteria ?

I guess that for a whole company (typically infantry), it has a company leader, and there's nothing to cross-attach.

Now if I buy 2 tank platoons. Am I supposed to cross-attach them ? What if they are not deployed in the same area ?

And what about combined-arms cross-attachement ? Typically, a tank platoon, mounted infantry platoon and AD platoon deployed in the same area, and going to attack together ? How do I cross-attach them ?