Wow. Can nobody look at this math and tell it is all wrong? If not, think about which Group you want to be in if you're a 73% team, the one with three other 70-percenters? No. You want to be in Group 2 of course. Group 4 is not totally bad for a 70-percenter, but just think about all the fun the 30% teams will have. They probably don't have a lot of fun anyway, but how many 50% teams want to jump into Group 4 and take their place? Seriously, who came up with this idea, somebody from one of those super-clans? Hats off to you if you did.
There is another way to do this, use handicaps. The handicap would balance total average damage capabilities between teams by limiting the number of players allowed in the match. If you have a clan that averages 1500 HP per game over the last 30 days, matched against a clan with an average of 1000 HP per game, the better clan would have to sit out at least 2 team members. That would match 5 players with a total average damage of 7500 HP per game against 7 with a total average damage of 7000 HP per game. Alternatively, have the better players use lower tier tanks to balance the average damage capabilities. Whatever approach is used, match average damage dealing capabilities between teams and let tactics do the rest.
I have seen Tier X tournament replays on YouTube where a clan with 6 players wiped out a clan with 7 two out of three times. If you're good, you're good. Take the handicap and show everybody your stuff. Wins won't be "easy peasy" for the good teams, but it will make the tournaments more competitive and probably more fun for everybody.