Will the semi finals/finals quests be better for grinding medals?

As far as I understand the drop rates are the same just different enemies.

It's the same droprate, only change is enemy composition.

For medals, for the most part, the drop rates are pretty similar, though certain metals seem to increase 10% in their highest appearing nodes per section (going off of just pop up pirate and team France nodes). The drop rate for the CE is exactly the same. The ace and skill mats dropped are different (IE, Pop up pirate gives proof of hero and rider piece, while team France gives dragon fang, caster, saber, and assassin pieces) and the rates are somewhat different there.