Speaking of random ideas: dump the globals into functions (one function per global) - that's right a dumb single-variable function. You can't monitor or pop an assert on a variable, but you can put slap asserts inside a stub function, etc. Plus you know a function ain't local. Globals are such poison that the minor inefficiency created by converting a few globals to functions is usually meaningless.

I begin to think that we need a richer vocabulary to address "complexity." To analyse it into various forms, (some of which are likely to be beneficial.) Separating code into lumps means more lumps; but fewer dependencies, more known absence of dependency... We keep using one word "complexity" to point to various things. Distinguishing between Complex(opposite of 'simple') and 'complicated' (opposite of 'easy') is a start I suppose, but I can't help thinking there are more careful distinctions that could be made.