Gimp help needed

Hi…I am using gimp to make collages. The gmic plug in makes it so easy to add shadows.
I use up to 60 pic’s (as layers) on a 4800 by 7200 area. my pic’s vary from 5 to 7 mb…
anyways my question is… Is there a way I can auto size al the pics to fit in the area.
right now i resize them one by one. takes a bit a time. so i thought id ask.
I have to admit Im not the sharpest tool in the shed. so scripting is out for me…lol
Thanks in advance

Could you provide an example of what you want to do? Or at least a diagram?

I would like a way to auto fit all 45 pic’s into the area.