I fail to see your point. To me, these three are all very close to each other in "simplicity" and any ordering seems arguable. If anything, isn't Perl simpler than Python and if not, why?

Perhaps vast differences in ergonomics and language-culture-fit but that's orthogonal/unrelated?

Lua is great, and `eval "$(luarocks path --bin)"` in your ~/.bash_profile or ~/.bashrc seems fine, better than Perl's where you gotta export PERL5LIB, PERL_LOCAL_LIB, PERL_MB_OPT, and PERL_MM_OPT, for example.