I am sure he tried and failed to take Kos down many times in that fight. They don't need to out wrestle GSP they need to stop over half of his shots and commit to their strikes to have a decent chance of winning.
You make it sound so simple. Stopping one or two over the course of a fight is probably possible.
I don't think anyone at this point at 170 will be able to stop half of his shots AND commit to strikes against GSP. There's a reason why 30 seconds into a fight, people aren't pulling the trigger or are on their back.