Not sure I like tying your "self control" skill to intelligence. On the surface it seems like a good idea, but wouldn't it be more "realistic" for the more intelligent characters
not to stick their heads out into incoming automatic fire?
How does it reflect the very low intelligence, low combat experience characters with more bravery than common sense or self preservation?
How do you deal with the armchair soldiers who believe that just because they've seen movie action heros shrug off a dozen bullet wounds and keep going, they can do the same? Sure they might change their mind after the first round rips into them, but what if they get lucky and don't get wounded until say their tenth or even hundreth combat?
How would another character using Peruasion, or Leadership skill influence the "self control" roll?
You make the rule, we break it for you!
