There's already an easy way to solve this: $PATH.
> I think a better question for you: What's the benefit of putting .PHONY recipes in Makefiles, when you could just have a directory full of shell scripts. If you find yourself using .PHONY recipes, then you already have a reason to use just.
Well, I think it's the same question, rather than a better question. And the answer is yes, if all you need from make, now and in the future, is a set of .PHONY targets, then by all means just use shell scripts. make is used because often you need slightly more than this -- or you may do so tomorrow, and don't want to change the syntax you use to accomplish tasks.