My suggestion for a proportionallity and have low avq managers, needing an effort, and 180% tankers, too with the need to do an effort is the following;
We set, the L5 Max. Avq to 130% so 7*
Then if a team surpasses 1 or 2 stars this AvQ, this will see reduced to 50% or 1/4 the points achieved VS the last oppo'
So a 8* vs the 130% last oppo would only collect the 50% of points compared with a 129%-
and a 9* 160%+ would collect only 1/4 creating a proportion in where High AvQ tankers would need to play more matches in order to gather points, so, this could create a fair proportion.