The fact that the top 20 bonus applies to the whole groups score I'd say your conclusion is wrong.
The whole group doesn't appear in the ranking. Only the person who turned the stuff in. You might say it doesn't matter because they all benefit in the end, but the point is that assuming only one individual from any group turns stuff in, that means there's a maximum of 20 groups / linkshells that can get optimal drop rates. Everyone that wants to pick up and play hamlet defense is SOL.
The whole point of my posting is that the ranking system DOESN'T NEED TO EXIST. It doesn't help anything. You can argue it doesn't really hurt anything in the end and I'd see where you're coming from (but still disagree), but you could just remove the whole ranking system and Hamlet Defense would keep on ticking all the same. It's just a wasted system that at best gives some people a chance to stroke their epeens and at worst may hinder some groups.