why during cutscene its always like this ... (small spoiler)

[Kurogaea]

And having one for each class is a waste of resources.

Besides, how are you going to have the opponent react? A BRD bow attack is dealt with differently than a WAR axe cleave.

You'd have to choreograph the ENTIRE FIGHT to accommodate each class.

AND race. A sideways swing from Derplander would cut a male Elezen in half, but go straight over the head of any Lala.
The only epic cut scenes we'll get are the CG ones with our Derplander avatar

Then you accommodate each possibility. Quit thinking SE are a bunch of lazy workers who can't animate a character model. They could've done it but they didn't.