Increasing the number of units in a chapter[RESOLVED]

[Seiya]

Hello! I'm new to the modding community, but I've gotten a hang of things over the past two weeks. However, I've run into a problem I haven't really found a solution for online.

In the prologue of FE7, it only allows for four units, when I want to add more (as I want it to be more than just a tutorial level)

What solutions are there?

(I attached the example image from Nightmare which shows what's going on.)

 

EDIT:

After a long time of searching, I learned about the helpful tool known as FEBuilder and that has helped me a lot with my romhacking. 

Edited September 29, 2018 by Seiya