What camera+lens is better for stage photography?

There is a group of stage photography in my Baidu space, you can refer to it.

I used 5D2+70-200.

But experience tells me that the focal length of 70-200 is still short. You can buy 100-400 or use 70-200 plus a dual range finder.

If you like to shoot Peking Opera, if you can get into the backstage dressing room, you can take some makeup photos of the characters, just focus on 50 1.4.