Quick question

[lysarin]

Which file(s) should I edit to change the start and end date of a campaign and modify the starting troops in settlements?

[Myrddraal]

The file is called descr_strat.txt.

Have you made a provincial campaign or do you want to modify the imperial campaign?

For more info on editing campaigns, heres a guide:
https://forums.totalwar.org/vb/showthread.php?t=39456&page=1

[lysarin]

mod the imperial campaign