Could I :
regroup all those pages into one which would look like the last one I linked ?

try to find as many campaigns as possible which are not in the wiki to add them ?

Add the authors to the tablers ?
This was discussed but received a lukewarm response, since many campaigns don't have a clear-cut author and have an entire mod team behind them. To some extent I agree and disagree, I recognize that a lot of people contribute, but I think a lot of times there is a prime mover. Also, a lot of times campaigns are largely the work of one individual. If you can address this issue and still put names, I'd say go for it.
I'll get rid of the "date" column in put in my attempt of ordering them completely (or almost, I ll just put the date, if there is one, in the description of the campaign).
Not quite sure what you mean by date... if you mean "Pre-Great War Era" and stuff, leave those in, as those are pretty important to the ordering as they mark the events of FS1 and FS2.
Or maybe there is a reason I don't know yet for having 3 pages for the campaigns, in which case I ll just upgrade the FS2 campaign page.
No reason other than when the last page was made, there wasn't anybody who was willing to take the time to research the campaigns well enough to finish the list beyond what is already there. Somebody offering to get it done is awesome.
