It seems very plausible to attach his quip to Lenin, as the Red October and its aftermath was practically exactly that: take action and see what comes out of it.
It seems very strange to attribute this 'motto' to Napoleon who is often portrayed as far more into planning and strategy and tactics. Well, for most of his career. The beginnings might be a little ...
'On s'engage partout, et puis l'on voit' appears in Literarisches Wochenblatt, Volume 3 - but not attrbuted to Napoleon, though he is twice mentioned in the short article. So we are now back to 1819, in Napoleon's lifetime. Perhaps this is a proverb rather than a quotation?
This looks pretty much like a conflation of the type already mentioned in comments:
Are you, perhaps, thinking of Samuel Johnson's dictionary, where he described oats as: "a grain, which in England is generally given to horses, but in Scotland supports the people"?
A few indicators to support this assumption:
Such description is ...