In tFoH, just before he leads the attack on Rahvin, he thinks clearly that strength did not have much to do with Gateway size:

Four paces was as large as Rand could make it. There were limits for one man by himself, Asmodean claimed; it seemed there were always limits. The amount of saidin you drew did not matter. The One Power had little to do with gateways, really; only the making. Beyond, was something else. A dream of a dream, Asmodean called it.

You need the OP to make the weave, and depending on the level of your Talent with the weave, the minimum amount of OP you need to put into a Gateway will differ. Sorelia, for example, seems to definitely have enough Talent to make the weave. But she's so weak the weaves don't hold. Androl is also very weak. But he has a much higher Talent. So he can make actual Gateways, even very large ones, even though he doesn't have access to that much more OP than Sorelia.

On the other hand, Flinn can put a lot more of the Power into his Gateway. But he can't make them as big because he's stunted by his relatively weak Talent.

With just those three examples, the relationship between Talent and strength in determining Gateway size is readily obvious. Add in Reanne, Aviendha, etc. and the only way you can claim OP strength is the sole determiner of Gateway Size is if you totally ignore the books.