There seems to be three ways I could handle this.

• When I have to change a variable, check everything else that might require that variable to be changed and make all the changes in a relatively confined area. Only one comment on the use of the variable would be needed.
• Use subroutines for major divisions of the script and when they would make the script shorter, with comments to avoid problems with variable interdependencies. This is what I'm doing.
• Use subroutines or objects to avoid problems with variable interdependencies, in addition to subroutines for the major, parent divisions. This is what people are suggesting.

In my case, using comments rather than subroutines or objects for my array triplet (actually, I just realized it's a quadruplet) avoids problems with variable interdependencies just as well. It also makes my code easier to follow and understand, run faster, and easier to develop (especially for me).

Yesterday, I forgot which of those arrays had been added to by a certain point in the script, and I wanted to splice those that were added to. Rather than permanently using a splicing routine that checks the length of the arrays, I used such a routine as a debugging tool only, found out which arrays had been added to by that point, then permanently added lines to splice only the arrays that would need splicing at that point. In addition to preventing having to dig deeper into the code to understand it, my unconditional splicing makes apparent which arrays had been assigned to by that point in the code, which could be useful for future maintenance.