something more dry about knowledge when set next to understanding

Yes, I know what you mean

But I wonder if that is an overlay of meaning you are applying because that fits your sympathy and general outlook? How about an alternative view that goes: understanding = theoretically based computation;
knowledge = digested and applied wisdom.
But let's test this out, 'cause I'm just thinking aloud (or should that be aboard).

I agree that I would'nt claim knowledge of French. But I might say "I know French". That seeems to me a very definitive statement, compared to "I understand French". In the latter, I can probably answer the phone and have a business conversation - in the former, I am halfway thro' La Rechereche de Temps Perdu (if I had the time )

What happens if we try substituting other words?

I know London = I am extremely familiar with the English capital's geography, where to go to eat, the tube system, etc...
I understand London = I know what sustains the economy of the capital, know what many Londoners feel about fox-hunting, the price of beer, and the Queen Mother, etc...

I know the depths of despair = I am trapped in an office almost anywhere in the world
I understand despair = I sell counseling services

I know penguins = I have had an embarassing experience being arrested at London Zoo...
I understand Penguins = I know how interested they are in eating fish

So I reckon maybe your colouring of the word is partly dictated by what a warm and cuddly human bean you are, and the importance you attach in life to really understanding people. What do you think - have I misunderstood you?


PS GROK
The West Country dialect of England (of which Cornwall is the most distinctive, with it's own language) has grockle as a disparaging term for tourist or holiday-maker (now that itself is a weird phrase, when you stop yto think about it!).