If we're sharing ideas for how an AST card rework could have worked, I personally would have liked to see a change that struck a middle-ground between the flavor of the current system and the consistent homogeneity of the 5.0 system.

I think a solid approach would have been to simply give all cards two effects- one consistent DPS increase, and another, more flavorful secondary effect.
I.E.

Balance: 3% damage increase + 5% Direct Hit Rate increase
Bole: 3% damage increase + 5(-10)% Damage Reduction
Arrow: 3% damage increase + 3(-5)% Attack Speed increase
Spear: 3% damage increase + 5% Critical Hit Rate increase
Ewer: 3% damage increase + Refresh
Spire: 3% damage increase + 5(-10)% Healing received

Lord/Lady: 5(-8)% damage increase for Melee/Ranged, respectively.
Divination/Seals: Keep As-Is

Though I can't speak for how the exact numbers would play out, I think that dialing back the potency increases to justify secondary, more situation effects would go a long way towards inflating the feeling of player choice as to how cards are used.
As a final note, I'm actually pretty excited for how new AST will play, particularly for its new emphasis on DPS boosting, but I do think I'll miss the flavor that came with the original six-buff system.