Ok, I get the impression the Weapons were created by the planet, in order to protect itself.

So WHY is it, that, on Disc 3, do Emerald and Ruby Weapon, easily the 2 hardest creatures in the whole game, sit there and do ABSOLUTELY NOTHING apart from put up a half-decent fight if attacked?! Why aren't they attacking Sephiroth, or say, attacking Midgar which is sucking up so much Mako?

In fact, only one Weapon does anything like that. Diamond attacks Midgar, and, in particular, the Shinra HQ, which is of course the main benefactor in draining the Mako. Even then though, it seems as though Diamond protects Sephiroth.

And the only thing Ultimate does is to attack Mideel, the least disruptive human settlement on the planet.

I just find the behaviour of the Weapons realy strange. Anyone able to suggest reasons for what they do? Please?