I don't know man, I'm not even sure I've seen them in order because I saw the maya episode like 2 weeks ago and the viking one last week (which I caught on Thurs). I'm awful with TV schedules, I usually turn on the TV and am surprized something interesting is on.
They keep running them over and over, I saw the Viking episode again last night. Just keep your TV on the History channel or look for it on the guide, it seems like one of those shows they rerun a lot.
One of the things they did not cover was how long it took to build a fort. They showed the fort and talked about it's pros but never mentioned how long after landing somewhere they could have a fort up.
I caught the Maya one, pretty well done. We had been having a discussion on another forum about the Aztek mācuahuitl sword, and the Maya war club is similarly constructed. Obviously an effective weapon.
I see there's a show that's going to premiere on the Spike channel that purports to examine "the greatest warriors", but it would seem to be more entertainment-oriented.