But why would the lines in the 2000 case be easier to review per line?

Which of these programs is easier to review

  {x{x,sum -2#x}/0 1}

or

  def f(n):
      if n <= 1:
          return n
      else:
          return f(n-1) + f(n-2)

They're both the same program

Good question.

But it is orthogonal to the question of evaluating 2000 lines of AI code vs 200 lines of human written code. Either the human or the AI could produce idiomatic code for either language, given sufficient training data in the AI’s corpus for the language.

My guess is that the first one is much quicker to review, for a human equally fluent in both languages.

Holy shit, read the words I wrote. Ceteris Paribus. Assume the 200 lines and 2000 lines have a similar distribution of complexity.

Romanes eunt domus