Although a player may engage his or her infantry units using the "F" key, I have observed that when I select target using the "T" key and thereafter selecting a weapon with the "W" key, the assaulting unit is not suppressed, even from within 50m. In this exercise I selected cavalry scouts assaulting T-62Ms with AT4 LAWs.
1. Press "T" key. Select Direct Fire for Current Unit
2. Press "T" key, Select this Unit as Target
3. Press "W" key, Fire Only the Selected Weapon
See unit D3:
When scouts engaged T-62s with direct fire using the "F" key, the scouts experienced substantial suppression in the range of 11. See unit E1:
Set Direct Fire Target Vs Fire Weapons at Target
Threaded Mode