That's not a good analogy. Chickpeas and garbanzo beans are just different names for the exact same thing. A better analogy would be different wine grape cultivars, e.g. Chardonnay and Cabernet are the same species of grape, but obviously have quite different taste and features.
While hemp and marijuana are the same species, there is a legal definition that is based on a real, scientific difference. Namely, that hemp is a low-THC cultivar of cannabis sativa.
> A better analogy would be different wine grape cultivars, e.g. Chardonnay and Cabernet
I'll take your word. I know literally nothing about wine except that some are red and some are white, and that they all taste like sweetened vinegar with a splash of paint-thinner.
> there is a legal definition that is based on a real, scientific difference. Namely, that hemp is a low-THC cultivar of cannabis sativa.
Do you mean THCA? What is the "real, scientific difference?" Marijuana naturally has high amounts of THCA and low amounts of THC. High THCA hemp has... well, high THCA and low amounts of THC. Their strengths might vary to some degree, but I would say the only true distinction of is just how they are legally defined.
Plenty of hemp is grown in my state, in which marijuana is still very illegal and very harshly punished, yet some of the hemp grown here is coming in at 15%-23% THCA range at the upper bounds. That is not what I would consider a "low-THC cultivar."
If you get pulled over while in possession of high THCA hemp, good luck convincing the police, "it's just hemp." You might be able to beat it court, but like saying goes, "You can beat the rap, but you can't beat the ride."
Yes, it metabolizes to the same thing, which is the point. This is also true for the pure synthetic stuff like Delta 8 and HHC. Even CBD has been known to regularly test hot.