One Madara didn't stomp them by any means. He resorted to his most powerful technique to defeat them.
They certainly put up a tougher fight than Naruto did. They countered his meteors, when there where only two of the Gokage there.
They countered his Mokuton, and more importantly Advent World of Flowering Trees. Something Naruto would have been hard-pressed to do if being attacked by Madara, whilst being put to sleep by the trees, while a fire rages within the trees.
The countered his Katons.
They didn't have an answer for his strongest move. That's it. They had an answer for everything else.
That isn't a stomp.
Also, that's not the point of this thread. The point is that he used PS to defeat them. Even said "to have to do this again." Because he believed they were powerful opponents deserving of the mantle Kage and he apparently believed they had a counter most other things in his moveset. He hadn't decided to go after Naruto until after that comment. So at that particular moment they were all that he was focused on.