I have five Echos and a dozen or more Hue lights, so it may sound funny for me to suggest you keep things simple. However, I think you were on the right track at the beginning. If you name your lights logically with standard obvious names, there should be no confusion. Unless you live in Hearst Castle, you probably only have a half dozen easily-named rooms; I'd stick with those main names. Name main ceiling lighting "Master," "Joe, "Kitchen," or "Jane," etc.) and additional smart lighting in that room (e.g., a nightstand, desk or lamp) by adding the appropriate suffix: "Master nightstand," "Jane's Lamp," etc. Also, you don't need to use the word "light," in invoking a command (unless you specifically called your workbench light, say, "Workbench light" instead of simply "Workbench"). The word is superfluous and you can save yourself the breath from speaking that extra syllable. Get into the habit of saying "Turn on Porch" and "Turn on bathroom" as opposed to "Torn on the porch lights" or "Turn on the bathroom lights." Truncating your phrases will help you as opposed to annoying you. This is why you purchased your Echos in the first place.
Ultimately, I think you need to concentrate more on educating those in your household what the rooms and lights are called. Yes it's a learning curve, but if you give them reasonable names, the curve should be small and the names very easily learned with little effort. Conversely, I am not convinced that Alexa won't be confused if it hears the same "turn on lights" command in every room for that specific room if you try to accomplish this with groupings. I'm not calling it tricky, I'm saying it isn't possible. Of course the tried and true standby would be "Alexa, turn on bedroom" (if you have a single, or group of lights called "bedroom.") As far as I know, any group name is shared and understood by your entire stable of Echo devices so would not work. However, if anybody's actually done this successfully please let us know -- I'm certainly happy to be corrected if I'm wrong.
Best of luck and enjoy!