Correct, they did it without linking. Each channeller weaving flows individually rather than being directed through the leadership of a circle.
Dangerous, risky and more difficult............. but possible.
Men can't link without a woman at all.
The rules:
I do and it doesn't.
Most of the information about the seals comes The Strike at Shayol Ghul and that only mentions the focus points and makes no mention of who constructed them
The BWB doesn't shed any better light either
It's certainly possibly he personally made the physical focus...
Well sort of, there's no recorded history of who actually created the cuendillar focus points.
It's a good bet that LTT was involved in group channeling effort to create the actual seals, but there's no way to say who created the physical cuendillar discs.
Could have been him I guess, but that...