The saints are ridiculously fast, they're MFTL
They were dodging light speed and FTL attacks from Gold Saints and staying on par with Gold Saints like Scorpio Milos (Blitz two bronze saints, both with the seventh sense), survived and fought Gemini Saga who's punches can pierce Gold Cloth and move FTL, and dodge attacks like Lightning Plasma (A billion punches per second).
There's no way Bills is going to be on par with their speed, especially not in H2H combat.
That and each of their attacks are hax with the ability to atomize their opponents,
Gemini Saga could release the force of the explosion of a galaxy.
Seiya's Pegasus Ryu Sei Kei stalemated Leo's lightning plasma
Shun's chains are cross dimensional and FTL
Ikki Phoenix can't die, even after having his senses removed and his brain destroyed/fried by Virgo Shaka
Hyoga has absolute zero and FTL ice attacks that freeze at absolute zero
and Shiryu has FTL combat and the sword of Excalibur that can cut through anything at a atomic scale
Bills could give a fight but overall the Saints would take it unless it's before the Temples Arc