Think it through guys. The most obvious examples we have of Talents that are anything BUT rare are Healing and Traveling. They both involve weaves and nearly every Channeler we've come across has at least some ability with them. The level of ability is what fluctuates from person to person. Greater Talent means greater ability to modulate the weave and thus create a wider array of effects than others. With Healing this generally means a woman can Heal more serious wounds, or like Samistu can lessen the shock to the patients body and perform a delicate healing with a fundamentaly blunt weave. On the flip side Egwene can't even close Gawyns wounds fully despite a massive strength difference. Same holds true for gateways. Androl can use a drop of the Power to make one large enough for a wagon, but Flinn pours exponentially more power into a smaller gateway.

This is not a case of the talent itself being rare, it illustrates that there are extremes with Talents. It also proves OP strength is not what determines the end effect of weave involving a Talent.

I wonder what would happen if Androl or Flinn were given angreal ... Would they be able to make larger gateways or would they simply be able to make more gateways of the same size ... Rand seems to think there is a limit to the size any individual can make, and he clearly reached his max size gateway with only a small portion of his strength and thus generates many at the same time. I suspect we would see multiple gateways of the same size rather than larger ones from Flinn, but possibly larger ones from Androl. At least until he reached the edge of his talent.