In that case can we lower attack range of Squall to a more logical number then? So, that it isn't fired so haphazardly without achieving much? Or do you need it to be long-ranged?
Well the Squall being long-ranged is part of what makes it so strong. It suppresses the enemy fleet and prevents them from mounting an effective offense even before the fleets close in to weapon range. So if you decrease its range, it really changes the fundamental nature of the weapon. However, I think it comes down to how you're using it.
The Squall has a period where it's firing continually and a period where it's on cooldown and thus the enemy fleet can recover from the barrage (or make their counterattack). So if you have just one or a couple of Squalls in your fleet, then they won't really do much; the enemy will just recover during the Squall's cooldown, or simply move around the line of Squalls.
If you have multiple Squalls in your fleet though, chances are they'll be firing at different times, and so their cooldowns will also be at different times. And thus what the enemy fleet sees is a continuous stream of incoming Squalls coming in from different directions and crisscrossing the fleet, which prevents them from recovering and thus makes the Squalls that much more effective. Putting multiple Squalls on one ship won't have that effect, because chances are those Squalls will have the same or similar timing, so you wind up with the same problem. So it's better to put Squalls on different ships. That's why I recommend, if the ship has 2 large missile slots, to use a Squall and Locust (linked in same group to have the Locust fire more often) instead of 2 Squalls.
It's one of those weapons (which is a general characteristic of many missiles, actually) where one or a few won't do much (i.e. you won't really see how well it performs in the sim), but if you start amassing multiple ones for full fleet-on-fleet action, it'll really start overwhelming the enemy fleet.