The important things are always simple. The simple things are always hard. The easy way is always mined. If you are short of everything except enemy, you are in combat. When you have secured an area, don't forget to tell the enemy.
Incoming fire has the right of way.
Friendly fire - isn't. No combat ready unit has ever passed inspection. Things that must be together to work, usually can't be shipped together. Radio's will fail as soon as you need fire support desperately. Anything you do can get you shot - including doing nothing.