If you are reading this that might be because you want more information, so here it goes:

If you want to add modded factions, just open the FCS, select the mod and base data of the game (gamedata.base, Newwworld.mod, Dialogue.mod, rebirth.mod)
then go the "changes" look for "retribution for the 100 man army" once inside go to "faction relations" and "add" and chose your custom faction,
then add a -100 at the side, after that you will be hated by that faction, but that won't affect raids, to edit the raid lenght double click
on the faction, look for "campaigns", now edit every campaing as i did, travel speed "Jog" so they won't be walking all the way, also change "ignores nogo zones to "true"
change the chance per day to 1, so they will always raid 100% of the times, range far 999999, range near 999999, make sure is six numer 9s
because that will cover more than the whole map, but 99999 won't do it, repeat limit is the amount of days that need to pass so they can raid you again,
if is a weak raid (20-40 combat stats) i recommend 1, if they are really strong 5-7 (once per week). It is important to know that "trigger events" happens
once a raid failed or succeded, so you need to put the "normal" raid lets say 1 time per day, if they lose the "trigger" will happen and they will send
a weaker army lets say, that is other raid, you need to give that one 2 days instead of 1, it can work with 1 but you don't want that haha

And that's it, that would make them raid you every time they can once you build an outpost.

You are free to edit this mod and use for whatever you want, i just did it for fun.

Nehe.