To the contrary. Because English draws from French and German, it doesn't naturally lend itself to analysis with grammatical concepts. So Latin is the better avenue.
But more important than that. When you study English for grammar's sake, you don't learn English. You learn grammatical vocabulary. Whereas if you're translating from Latin to English, you simply learn the the grammatical vocabulary along the way, as a tool.
Ich erhebe Einspruch!
German is an inflected language. Not as much as Latin, but it is still possible to determine the function of many of the words in a sentence based upon their differing spellings.
Hochachtungsvoll,
Euer ergebenster Diener
When I was a kid we were taught english grammar, diagramming sentences and all. But I never really understood english grammar until I learned Spanish grammar.
So your point is a good one, that learning Latin (or any other language well) will improve your english.
But for me, the reason to learn any language is to use it. Learn Latin, for example, to read Cicero in the original. Learn Spanish or German or whatever to open doors intellectually, not just to be able to travel though that is important.
I disagree with some who think its sufficient to be able to order a beer and ask for the restroom. There is a world of thought and knowledge that for me should be the purpose of learning a language.
I was reading recently Ben Franklin’s memoirs... he was self taught in Spanish, French, Italian, and Latin... just so he could read their books. Of course, later in life he wound up living in France, so learning to speak the language would have been that much easier as he could already read the language.