Admittedly that chart is a little hard for me to decipher, but I think it is applying to one single shot. However spread over an entire OB, over the course of of an entire scenario, I would think the effects of not-cowering would be more profound. Or am I wrong?
Keep in mind that Medrow's analysis is predicated on a target having a ML of 7. The effects of Cowering are a bit like the effects of a SAN 3. The longer the scenario, the more likely one or the other will have a significant effect on the outcome of the game.
If I understand Medrow correctly, he is saying the probability that Cowering will increase
the likelihood that a given shot will have no
effect on the target is marginal when low-FP shots are ignored. For instance, when a 8 FP attack is reduced to 6 FP for Cowering, the probability of the target not
breaking or pinning as a result of the attack is not as pronounced as one my expect it to be. EX: A FG containing two 4-5-7 rolls double fours on an IFT attack. Normally, this would result in a NMC. But because the attack is now resolved on the 6-FP column, it is only a PTC. Medrow's data suggests that despite the shift, the unit taking the PTC will only succeed
Having said that, were the Latverians (or the Wachovians) force composed largely of First Line 3-4-7 squads, Cowering would presumably have a greater impact on play because the bulk of FP attacks would be in the lower range, where the effects of Cowering on outcomes are
Look at it another way. There is roughly a 3 percent probability that Italian MG will malfunction when fired, whether directed by leaders, or not. It stands to reason that this will reduce an Italian player's ability to break or pin enemy units during the course of a scenario. But by how much? By enough to keep you from firing them unless a target is moving in the open? Probably not, because you need to fire on a target in order to get a result, and even a lousy NMC can be a game changer.
As I stated earlier, unless laying a Firelane is critical to the success of your plan, the risk of Cowering should not, in and of itself, deter you from firing. There are many more important things to consider, e.g. enemy units still to move, etc.