I'm considering using subagents, as a way to manage context and delegate "simple" tasks to cheaper models (if you want to see tokens burn, watch Opus try fixing a misplaced ')' in a Lisp file!).

I see what you mean w.r.t. different hats; but is it useful to have different tools available? For example, a "planner" having Web access and read-only file access, versus a "developer" having write access to files but no Web access?