To each their own... The way each has stated it can be done... can be done. I like e that we all have so many options.
To the last entry by DroMike, I just have to share this funny one for you (and anyone else following) I set up a single bulb in my aunt and uncle's house, so she, being quadriplegic, could summon him when he's out of earshot (which isn't very far as he has hearing loss pretty severely). I named the bulb Richard (his name) and gave her the command line to workout out... Yep... She says "Alexa Turn Richard On" and they always Still get a chuckle... He sees the light in the other room and goes to help her out as needed. How much fun is it to set up commands that are a bit risqué? LOL These are older folks (I'm in my mid 50's and they're older than me by at least 10 years), so it makes it even more fun when they have company and she shows off her ability to turn on Richard, right there before their eyes!
Anyway... name them what you will, have fin and enjoy the technology. Use your imagination to make things work more like what you want them to work... if you want Star Trek... Give it some Star Trek feel by the way you name it and use the "Computer" alternate name... that kind of stuff. which is also a way to separate two Echo's that are close to one another... use the alternate names to keep one of them from hearing you talk to the other. They can all have their own name (within the four options).
Hope any of this helps or entertains...
I have 2 Echo Shows, 1 Upstairs and 1 Downstairs, and an Echo Spot in my bedroom as well as in each one of my 2 daughter's rooms.
I also have a fully automated home using Control4, which I've connected to the Echo device, and it has the ability to turn on/off /dim specific lights, turn on/off/dim every light in a specific room, and using Control4's system, I'm able to setup specific Scenes where it will do multiple things at one. For example, in the morning, I tell it good morning, Alexa tells me good morning, then turns on 75 lights around the house, all to a specific percentage level of brightness, unlocks the doors, turns on the TV in the living room to CNBC, changes all 3 air conditioning units, opens the drapes in the living room, my office, my bedroom, my daughter's rooms, the master bath, and the media room, and then she gives me an update on everything that's on my calendar that day, plus the weather, and some news I've chosen. I also have a Welcome Scene, which does something similar, but the brightness of the lights are different, some of the lights are different, and depending on if it's bright outside or dark, it automatically turns all the lights to a different brightness level.
The best way for you to do this is buy setting up rooms and then assigning different lights/audio/video devices to each specific room. I'm not sure if this would work, but if you assign the Echo device to the same room, maybe all you need to say is lights. Another option would be to delete certain devices from each Echo so when you say turn on the lights, it doesn't see all the lights in the entire house. Then you could assign specific lights to each device, but if you did this, it would prevent you from being able to turn something on/off in a different room. I have an all on scene, where it turns on every light in the house, and I have a scene for my youngest daughter, who's scared of the dark, and she can say turn on my pathway and every light between her room upstairs down the stairs and into the kitchen turn on to 40%. This lights her path to the kitchen if she gets hungry at night.
I have a total of 448 smart devices on my Control4 system. Using the Control4 interface, everything is named differently, but I can name any device whatever I want Alexa to recognize it as, and it works great. Splitting up all of your devices into specific rooms would be a good start, and when you scan for smart devices and it comes back with a list, either try to assign them to a specific room, but you would have to say turn on the lights in that room, or you could go further and specify a specific light in that room. If that's too difficult, then after it's finished scanning for devices, delete every device that isn't in that room so when you say turn off the light, it only sees a couple. Then, on another Echo device, do the same, but delete everything that isn't in that specific room. If you do it this way, make sure you change to activation name on devices that can both hear you from the same location.