Actually every starship now sucks against them.. which is why you need your "flock" to kill them, with damage boosting very quickly too ;p
But ehm.. even if you reduce the range that doesn't change anything, i'd just merge my 2 fleets into one and get a more spread less even boost of damage, but any boost is a boost.
I am not sure what to suggest, nerfing them again will just lead to them not getting used anymore because thats the ONLY reason to build light starships
A 50% reduction in range might be worth a try, if fleet ships get something else
Or maybe we should talk about an complete replacement of the munition boosting ability line - with something else`?