As far as the problem is concerned, it's really hard to say whose handwriting is the best.
You can only answer the questioner like this.
Who is the most famous calligrapher in Shandong Province?
Wang Xizhi, a native of Wang Xianzhi, was born in Renlin, Shandong.
Yan Zhenqing, a native of Linyi, Shandong Province (ancestral home)
If you have to say who has the most calligraphy in Shandong.
I think Wang Xizhi did it!