I wonder if the proportion of 'students' of Musashi who use this phrase as a reason for no strategy at all is the same as the number of programmers who disdain optimization of any kind?

And the way of the grind. Or daily iteration.

"Today is victory over yourself of yesterday."

Who said that "unripe strategy" = "strategy defined too early"?

Thanks for your question. I grant you, it could mean that the strategic thinking of the strategist is still immature. But in context I don't think it does.

Musashi lays great weight on developing keen perception of the moment and its potential. When he says _nama_ 生 'unripe' strategy, I understand him to mean strategy that is settled before conditions have ripened. That's comparable to Knuth's remark about optimizing code. I don't think Musashi means that the strategist is too inexperienced.

Although there is a vein in East Asian military theory about wizard-like long-range anticipation of strategic conditions, Musashi doesn't indulge in that.

That could as easily go either way.