Probably not. I don't think that in the large that helps with readability / maintainability. Even in the small, I find languages which don't allow forward references (Ruby, sh) rather annoying. It forces relatively insignificant implementation details to be read first, rather than starting with the big picture of what the program does.

I would be interesting to do a similar study on some Factor code.

I would expect similar results. Factor and other stack-based languages are not particularly linear, thanks to, well, factoring. Sure, data flow generally runs from left to right and top to bottom, but word and tuple definitions are just as scattered about as in any procedural language.