If only we're on same server, I could come help. Already done all missions on each nations in WotG era myself, which I highly recommends any of you do them all. The story of each nations are really good IMO, at least way better compared with the original nation campaign for the current era.
Though probably best to finish at least 1 nation all the way along with WotG main campaign itself. The medal of Altana you get in the end will tremendously help when switching other nations to do their story counterpart.