Riveting top skin last?

[Chewie]

I'm getting very good results back-riveting the bottom skin so far (at the nose ribs), and would like to back-rivet the entire bottom of the wing if possible since it's more visible than the top. Most scratch-build instructions and videos I've seen show the large bottom skin going on last, but this prevents access of rivet gun to the inside.

Is there any reason I can't do the top skin last instead? Have any builders tried this?