Lexya I agree - their acting isn’t as natural but it’s understandable knowing that acting isn’t their forte. Jessica is more experienced in singing, modeling, etc... and Stephon is more experienced in professional basketball. But all in all, it’s okay because for them it’s for the experience 😊 and in other aspects (through the eyes of the entertainment company, management, etc) - marketing.
Connie C maybe she is this way because Yoona was supposed to be the actress on the group and taeyeon and Jessica the solo singers. actually Krystal also has the same role in fx that's why she can act.