Question about editor

[rancor26]

I just want to ask before i do any damage that if i for example use editor to edit (choose session "orcs" from the session menu) "orcs on the march" campaign will it overwrite the existing files that came with the game if i save the things i edited? or will i be able to play it as a individual campaign without the original game files being changed? or if i make a new session and load "orcs on the march" campaign maps there will it then be individual campaign? I'd also like to edit "defender of the crown" campaign but you can't even load its maps to the new session so the only way to edit it is to open "defender" session and if that overwrites the original files i dont want to do it.