Interesting question. I need to do this for a battle system I'm working on, but I only need to move one (the main) character, so I plan to make it dynamic. (he can move any time during battle.)
Your question opens a bunch of other questions: How / when can the battlers move? How will you choose which battler you want to move? Will this happen during the action selection phase? Are you using the default battle system? RMXP or RMVX?
Are there limits on how far the battlers can move? What is the advantage of moving?
To start, you'll need a good understanding of "Scene_Battle", and the different phases of 'turn-based' battle system. Then, you'll need to answer all of those questions for yourself to decide how to implement it.
If you are going to move during phase 3 (Actor Command), then you'll probably want to look at the actor_command_window in Scene_Battle. You'll certainly want to look at Spriteset_Battle & Sprite_Battler. You will be changing the 'x' & 'y' properties of Sprite_Battler when you move the battler. You'll also want to look at the 'Input' module, and the update method in Game_Player for an example of how the 4 directional movement is handled.
That should be enough to either start to clear things up, or thoroughly confuse you... :scruff:
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