Therefore it's a list based on a clan's strength, if proven strength is important in order to be placed there.
Nothing wrong with it at all, but a clan doesn't necessarily need to focus so much on it to succeed. I think a clan's overall success depends on whether or not it accomplishes its goals, but that's just me. That's why I don't think there should be an all-encompassing "Top Clan List", since clans of differing purposes cannot really be compared so easily.
Overall, if there is one change that I've noticed since 2001, it is that clans have really swayed toward PKing. In most MMO games which are not entirely pvp, clans can have many purposes, and the players of Runescape used to accept that. There was a
wide variety of clans which were successful on all ends of the spectrum. Some clans were based on a specific tradeskill or tradeskills in general, some were just for player associations, some were party-based, some were based on PKing, and others tried to focus on everything.
We tried to focus on everything. While we are not the best at a single aspect of the game, we are very competent in many different areas. We are perhaps among the most versatile clans in the game... And accepting all levels into the clan doesn't make us weaker, for they will eventually get stronger and also help to keep us real and not full of ourselves. The difference between our clan and other clans who formed when we did is that very few clans of decent size from that time period either remain or are based on the same things today. Many seem to value PKing much more than they used to, and while that's not necessarily a bad thing, it warped the definition of a clan.
Now many new players feel that a successful clan must focus on competency in the wilderness.
This is just me and from a neutral standpoint, but SeeD is one of the few remaining clans in the game based around older styled systems and goals... While we are competent in the wilderness, it is not an advertised purpose of our clan, and as a result we indirectly repel those obsessed with PKing. As a result of this we are probably the largest clan which is not stuck up on owning everyone else... The fact that such a large clan as SeeD can stay in the background of the Runescape community while still succeeding to this extent is tribute to our nature.
We help others when possible, build up our internal structures, and do not bother with the meddling of most other clans. This is probably why our community is so strong, some call SeeD the big clan with the little clan feel. Our community is such a focus that for some it overshadows the clan, but the clan is the heart of everything that is going on here. For someone who sees more in the game than just PKing, I think SeeD can be the most comfortable clan to which one could belong.
(sorry for the long post)