Is there a way to create animations with different sprites but with the same namekey?

Phaser 3
2

In phaser 3, all animations are global. You should be able to just play the animation on the group. e.g.

group.children.each(function(child) {
    child.anims.play('anim');
});

I’m not sure if this is best practice, but it’ll get the job done.
This answer assumes you want the the group’s children to all play the same animation. That’s what I got from your question. Also, the title is an x|y question.