Then why did you say:
You seem to be contradicting yourself. No offence.
I did them one after another.
They were saved and they were the right files, otherwise I wouldn't get a CTD all of a sudden, or the original name of the Juliii faction leader's wife would never have changed from Faustina to Metella.
Here are the files I'm working on. In these files I replaced all the vanilla names with those of my own, that is to say, in names.txt and descr_names_lookup.txt I didn't just add them to the bottom (although I've tried that as well).
As you can see, I've tried both modding them by using the method used in the vanilla files (spaces instead of underscores in descr_names.txt and in descr_strat.txt) and by using the method used in your tutorial (using underscores instead of spaces in those files).
Of course I had the files named like the should be when I tried.
I also tried all four combinations possible:
1: descr_names_version_1 + descr_strat_version_1
2: descr_names_version_2 + descr_strat_version_2
3: descr_names_version_1 + descr_strat_version_2
4: descr_names_version_2 + descr_strat_version_1
Please take due notice, I always delete map.rwm prior to making another try starting a new campaign.
Edit: I forgot to add, of course I also checked names.txt and descr_names_lookup.txt for any duplicates among the names.