Maybe the OP needs to clarify what type of "problems" exactly he is referring to..the examples he gives point to problems requiring significant engineering efforts, which is very different from the examples you note above.
I would go so far to say there isn't actually a dichotomy here -- you should be swapping between launching something with a hypothesis (in lean mode) then gathering feedback and considering alternatives as you are proven correct/incorrect (hammock mode). I think Galls Law [1] is also relevant here:
"A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a working simple system."
If all you do is think and think, then you open yourself to mis-timing a solution, feature and scope creep, and risking "unknown unknowns". If all you do is launch and incrementally iterate you'll be stuck solving very narrow problems.
[1] https://en.wikipedia.org/wiki/John_Gall_(author)#Gall's_law