I assume that the robots are god-level last-hitters and farmers. perfect farming efficiency is enough to beat 99% of human teams. most players struggle to get 50 last hits in the first phase of the game, nevermind actually get every single piece of eligible farm.
edit: i would also expect that the robots are deny nazis, who severely crimp the farming of anyone who opposes them in the lane.
That's not really the same version of the AI that's playing 5v5 now though. The Shadowfiend 1v1 bot was near perfect at all the skills needed for that match-up, while the current bots are far worse at even some mechanical skills like last-hitting.
edit: i would also expect that the robots are deny nazis, who severely crimp the farming of anyone who opposes them in the lane.