There's several features in the game that "speeds up" the gameplay. For one, obviously, increased resources means faster game so that could solve AI ladder games.

For players against players that want slow resources, keep in mind that people have 2 things that AI don't: bold moves and stupid mistakes. I've observed an AI ally on hard difficulty and he plays cautiously, keeping his cards close to his chest. He does attack and take planets occaisionally but most of his moves are passive, keeping him well defended but making no real advances in expansion. People do. They can gamble and attack a fortefied base or they can neglect a wormhole opening on their flank and lose a planet. Also, if you take out an AI's army they can recover quickly. People try to sum up the damage and pay too much time on saving the army, making the person easier to conquer and making the game end sooner.

I can't imagine playing a game of sins that last under an hour