What happens when the Commander squad is killed? From the preliminary manual:
The HUD center panel icons have changed. In addition to the Star for the Commander, there is now a Diamond for the new Commander. A Commander in Radio Contact will have his star colored green.
When the original Commander is killed or immobile a subordinate assumes command. The new Commander will have the Diamond on his floating icon and the HUD. A new Commander has the penalty of :
He no longer has a radio, loses the bound order, has a 5% higher chance to lose moral, and has a 5% reduction in experience promotional chance.
A secondary Commander may take control if the Commander is routed and retreats. There is a chance that the Commander will recover and re-assume command.
If the Commander is killed, Subordinate units will assume Defend orders. New orders are subject to delays based on rules chosen.
I just played a battle as Soviets. A platoon of 3 T34s has the Commander #1 and subunit #2 both received immobilizing hits in the same phase. Subunit #3 assumes command as he is still mobile. Later on, subunit three is destroyed and #1 again regains control.