yes, thats right, i didnt meant its exactly the same. On the CA blog is the example shown. Your right.

My point, to clarify it, you get 4 1v1 a lot quicker done, as a 4v4. While you could be able to win the 4v4 quick, to get it setup and find another 4v4 team will take time.
It might be best ratio, if you take the bonuses in, to play 2v2. There will be only clans who will run into the 3v3 or 4v4 games, while there will be a lot more ronins out.

You have one small mistake, as far i did read, only one will get the extra point of clan mate who participate.
At least on the blog there is pointed out, the max of 83 points.

So it would be like this: 20+20+20+20 and 1+1+1 (for the 3 other guys) = 83pts in total.
Still, it would be 3 more than playing 4 times 1v1. Just not enough imo to make 4v4 really worth to play for the points.