What a title, eh?

I'm currently designing a videogame; a turn-based RPG like Final Fantasy (because everybody knows Final Fantasy). It's a 2D sprite game.

These are my ideas for combat:

-The player has a group of 15 members (main character included)

-During battle, five of the group are designated as active, and appear in the battle.

-These five may be switched out at leisure, or when one of the five die.

-At any time, the Waiting members can cast buffs, be healed by the active members, or perform special attacks.

-Battles should contain 10+ monsters at least. I'm aiming for 20, but I'm not sure if that's possible yet.

-Battles should feel larger than normal due to the interaction of Waiting members, active members and the increased amount of monsters per battle.

-The player has two rows in which to put the Active members: front and back.

-Depending on the implementation, I might allow comboing of player attacks and skills.

These are just design ideas, so beware! I have not been able to test this out yet- I have no idea yet if any of these ideas bunched together will make for a compelling game. What sounds good on paper doesn't necessarily have to be good in practice!

What I'm asking now is how to create the layout for this. My starting point are the battles in Final Fantasy VI, with up to 5-6 monsters on the left and the characters on the right- monsters on both sides if it's a pincer attack.

However, this view would not work feasible with my goal of 20 monsters and 5 characters. All the monsters on the left would appear cluttered unless I scale them far far back. If I create a pincer-like map, then there would be no real pincer-attack possible. If I space the monsters out I force the player to scroll the screen- a game mechanic I've come across and not enjoyed imho.

My question is: does anybody have any layouts or guides for designing battle maps in turn-based RPGs, especially with a larger number of enemies taken into consideration? How should it look? I am not asking for specific combat mechanics, just the layout for the moment.