Meh, the point system itself changed in between the tournaments, how does that go with the so called credibility? Fighting in the first two (I think) tournaments gave winners more points then in the followings. Hardly fair. Also, I don't remember the Fallens every said it's supposed to be "serious" ladder, just because there were some tournys that in your book fals into serious category doesn't make it so.
The point system never changed, the formula was always
LP = (number of clans in the tournament X number of clans in the tournament - final place + 1 X size of clanteams). The first tournaments actually gave less points than the latest ones because of the lower number of clans who participated, but the formula was always the same.
Well, maybe a separate ladder for the more "fun"-oriented tournaments? That way, you could actually experiment more freely, without worrying about balance that much.
Some qualifiers will be in the classic clan vs clan format, some will be in new formats we want to test (like the 4v4v4 or the current 5x3 vs 5x3), so sometimes luck might play a more important role. Looking back at the past 5 tournaments, every time the best clans went to the finals (with very few exceptions when they were penalized). Finals will always be in a clan vs clan format, as balanced as possible so I see no reason not to award ladder points to the current tournament or to future ones where new qualifying systems might be tried.
As I said before, it would be a lot easier for me as organiser to make the same classic 2 groups clan vs clan qualifiers, than 1 group for finals but this would soon lead to routine and boredom.