I think that would depend more on the track, at that point.
At Road America or Daytona? I'd wager you're right.
But at, say, Little Tally (Talladega) in Birmingham, Alabama? That place is a goat rodeo, and I have seen 625 KTM supermotards beat the times of SV-1000s, Milles, and GSXR-750s. So while I haven't seen with my own eyes, a stock literbike beat a factory racer, I think it has more to do with 1) the rider, and 2) the track, then maybe 3) the bike.
On a small track, the power can actually be a disadvantage.