Much of 甄嬛傳's success was due to voice actress 季冠霖 who dubbed over 孫儷's voice. If Sun Li had used her real voice, the character wouldn't have been as believable. When I hear Sun Li's voice I immediately think about 周莹, another character she played which was perfectly suited for her voice and personality. By comparison, 蔣欣's voice is exactly 华妃, the match is perfect.