The problem I'm having with your argument is that it involves ignoring almost everything we see the weapons do in the game, and how the characters react to them.
We see Ultima get drawn to Mideel, coinciding with a massive movement of Lifestream/Mako. We see Diamond get drawn in coinciding with a large mako drawing project in Midgar, and then again when the start drawing heavily on the reactors in preparation to fire. Sapphire is the odd one out, but Tifa was in a coma for the previous days, we don't see what Shinra has been up to in the meantime. Thereafter, the surviving weapons do nothing unless the player picks a fight with them.
It's made pretty clear through the game that all Shinra have to deal with Weapon is Sister Ray. Consider the attack of Diamond Weapon. When they learn about it, the party (including Reeve, who would know) react as though the only thing that can stop it is Sister Ray. When they learn that that isn't ready, their plan B is to protect Midgar themselves. If Shinra had anything else, if they had any way to protect Midgar otherwise, why would Reeve not tell them they didn't need to worry, that they've fended off attacks before?
We see Scarlet's anti-Weapon artillery, and it isn't very impressive.
If this wasn't something new, why has Barret not been worried about Marlene's safety before now, if Midgar and towns across the world were constantly being battered with Weapon Attacks? Why would Reeve feel the need to announce this attack and not any of the earlier ones? How could Rufus defend anywhere that didn't have Sister Ray, when his gameplans to deal with Weapon all rely on it? In the attack on Junon, they lead with the cannon, and use 'regular firepower in the meantime' until they can fire again, implying they don't expect anything else to work.
Your Kalm NPC dialogue seems like just a reference to moving Sister Ray. No NPCs anywhere other than Junon reference witnessing or being a victim of a Weapon Attack, while nearly everyone in Junon does.
Against all this, you have one line from a man in prison for the last seven days, which isn't clear about what attacks he's referring to.
I will say you have a very mistaken, to be frank, view of creatures in this game that exist solely to carry out a specific task (i.e. to destroy) as lazy "gentle giants"
Not at all. I never said they were sparing human lives out of concern, just indifference. Their goal is to destroy threats to the Planet, and random towns don't seem to qualify. Their appearances consistently follow heavy movements of Mako, not random towns, otherwise any place that doesn't have Sister Ray protecting it would be easy prey. None of the characters that have hometowns express any concern that they might be attacked by Weapon. We see no damaged towns from Weapon attacks, and nobody even comments about any. Nearly all the weapons could squash any town they chose. Any big battle to protect, say, Gongaga, would be big news in the town, people would be talking about it, but we get nothing.
