1. That statement falls on itself because the important thing is who the Alliance beat, not the relative contribution each person made. If the WG and News Coo found out that Shanks and Whitebeard were defeated by an Alliance with Luffy, Buggy and Mohji as the most infamous people involved, the bounties would reflect an equal shared participation even if Luffy did 100% of the work. So Kid and Law having the same bounty means VIRTUALLY NOTHING considering what they did VS what Luffy did.
Nobody here is claiming Luffy = Kid = Law.
The point was that Oda would not give Kid/Law a 3 Billion bounty if he did not think they were insanely strong. It does not mean that Bounty is always a valid method of powerscaling.
2. "Oda won't give 3 Billion to someone who isn't a top tier" and "the threshold is from BB's previous 2.2 Bounty" are clearly gonna be shattered by Buggy's new Emperor bounty so guess what IT DOESN'T MATTER AND ISN'T USEFUL FOR POWERSCALING