For me is a little more complicated then this. I mean, top 10 tank are still the same as before.
Class change a bit the hero, but does not reverse all our charts.
The thing is how every player want to organize their deck and on who they want to give priority.
You have both Guinevere and Zeline? You have to chose one or the other, or upgrade both for half.
Then there’s 10 classes and 5 colors, so ideally you want 2 heroes for every color.
Then you have defence and titans. You probably want to upgrade first heroes that you can use in both.
Then you have stars. People who want to compete in rare or epic event can choose to upgrade first rare or epic heroes.
And in the end still we are not sure of every possible combination how it works.