Feedback Trying to figure out my camera views

I'll just preface this by saying I've only just gotten done with the UI module in the unity pathway so I'm still a total noob at this.
I had posted this over in Game Design but that probably wasn't the best place for it.

The basic layout of what I'm trying to do is: I'm gonna have a main scene that will handle most of the normal 'management' that the player is going to do in the game. Managing a town, building, making items, equiping npcs and the like. I plan on having 2 or more combat zones where most, if not all, of the combat in the game is going to take place (overland zone, dungeon,etc). Functionally, script and mechanic-wise, there is going to be no difference between the different zones, just different npc groups, tileset and enemies. Each of the combat runs that the player can start are independent of each other, and obviously the player can only look at one at a time.

Now, what I'm trying to work out is how to set the scene(s) up to do that.
A: Have everything all in one scene and use different camera views.
B: Have each combat zone in their own scene
C: Have all the combat zones in 1 scene separate from the main and have different view for each run (overland uses THIS camera, dungeon uses THAT camera)
D: combat zones all in 1 scene and set 1 view that changes the visual elements for the different runs depending on which one the player wants to look at
E: None of the above?

Any suggestions? And thank you, in advance.

FYI: Just to give you an idea of how the combat looks, it's going to be a side scroller 2D idle game. NPC group is on the left, enemy group comes in from the right, fightfightfight, repeat.

Above was the original post. After giving it some thought and doing some more google searches here's what I've come up with:
Have the main town view just be off to the side. Even though the player will probably be there the most, just about all of the action will be point-and-click, mouse dragging and the like.
All the combat zones are gonna be centered on 0,0 and this is where 95% of the 'moving parts' action is going to be. Each zone is going to be on its own layer with its own camera for that layer (overland on layer 5, dungeon on layer 6, etc).

I know this is a bit of a wall to read, but if anybody has any insight for/against the 1 zone per layer idea, please let me know. I *think* it will work, but figured I'd ask before I start getting too far into it. Thank you.