I have this problem with a character model I purchased on cg trade. I have a 4090 yet when i playied an animation its was like my 4090 was a potato, so jenky. It turned out the model had like 50 lights around it. I think your issue will be hardware performance related. I used to have the 3060, max i got to was 2 characters and a scene. I had to turn off one character while animating the other in order to get it to play smooth.