I'd imagine significantly worse, as usual
Most body shops should be significantly cheaper than the internal FAANG wage folks and of you don't cheap out too much about as good.
Remember the average tenure at Google is like what, two years? You lose almost nothing by going with contractors for two years instead.
Cheaper, not cheap, is the keyword.
Google programmer staff is way too big to be any sort of elite. They are not a 1 in 100 programmer.
Maybe the 60 percentile or whatever at their scale.
Since the stereotypical silly good programmer skill is negatively correlated with social skills it would not surprise me at all if the median Google employee is even below median due to their recruiting process.
I.e. their recruiting is worse than dice rolls.