I've had a Decker end up using 2 Edge because he was trying to score 2 Marks and then Trace Icon on six cheap commlinks and ended up with bad luck a few times. I also have rolled 5 hits on 6 dice and made summoners practically bleed as a result, so the same chances can easily apply forDeckers At that point threshold would be more reasonable, so only their own bad luck matters, not craziness in my rolls against them.
Automatically throwing all enemy pools to /4 seems too harsh though, but /3 should be plenty to balance things out.