They don't. When spinning the weave, the circle is the way to go, I think. It is only when long term maintenance of a weave is needed that they unlink.

Yup. Rand's shield (our best example) was weaved by thirteen LINKED sisters. You cannot weave one shield with unlinked channelers.

I'm not disputing this at all. If thirteen unlinked sisters tried to shield Rand, I doubt he would find it difficult to shrug them off. There is no way they can achieve the coordination required unlinked.

Thing is, if this was a circle, wouldn't he just feel one giant soft point? A circle works so that one single sister becomes the conduit for the power of everyone in the circle. How can there be six points then?

They are merely maintaining parts of a shield. Look at it this way...
A shield on Rand needs to be made of X saidar, which can only be gotten by linking. Once made, X saidar units need to be maintained in the shield. This can be done by tying the whole shield off (direct recharging of the shield from the source). This can be worked through, so it is no option.

Another way is if the circle leader continues to maintain the weave. This will work, but is overkill.

So, they take advantage of the fact that since X saidar is already there, all they need to do is provide smaller amounts of the Power to various parts of the shield, thus maintaining it at the same strength.

Yup. It certainly seems to be clear from that Egwene PoV, but not too many discussions have focused on it.