First:

"Luckers: Of the really strong channelers we know the nature to, all but one have been sparkers[10] . This has led to the belief that sparkers are on average stronger than learners. Is this belief justified?

Maria: No. “Having been born with the inherent spark apparently is not an indicator of strength. There are as many with weak potential who will channel whether they are taught or not as there are of great potential” (from Jim’s notes). The stronger ones just get more attention."

Second:

"For over 3000 years, though, Aes Sedai have been removing men who actually learned to channel from the gene pool. They have been very efficient at this. As a result, the "present day" sees about 1% of the population who can learn to channel, with a much, much smaller percentage of that being born with the spark."

But still, for the sake of argument, even if 20% of the channeling population were wilders, and even if wilders were all strong enough to become Aes Sedai, and even assuming that the 1000 novices contains no wilders, that still wouldn't be enough to make the numbers right.