HC-B would had had trouble with carrying around a large tripod and working the Zone System , out in the streets.
To me, that sort of proves that Zone Sytems etc. are little more than holy games that photographers play in the hope of making their craft seem more mysterious, more 'divine' than it basically happens to be.
Photography has got to be one of the most simple processes around. All that counts is what you do
with the thing, not which magic path you subscribe to as being the one with the shine. Hell, today you don't even need to know how to read a meter! Trouble is, the bit that counts is the bit you can't buy.