Player rating for tournaments across all installments of Heroes.

Occupied slots and their inclusion in the ranking introduce even more subjectivity, and also encourage the development of cooperative strategies, where several players from a clan can share ideas and push down the rest of the players following them. With your biathlon-like system, some players might not even receive a rating for a match during this process. :) ;)

No system is immune to this. It seems more like a conversation for the sake of conversation on your part.
And you haven't presented a main argument in defense of your system. Nor have I seen any drawbacks in mine.
I repeat, maps are inherently different, and it's not entirely correct to tie results to the leader. It's like considering the gap between competitors in a marathon and a 100-meter sprint. It's absurd.