The second is the form of expression, namely the form of books and works.
In terms of calligraphy style, Weibei is a typical one with a broad and powerful structure. Regular script represents Yan Zhenqing, with an extended structure, strong fonts and strong expressive force.
Formally speaking, calligraphy and fighting works emphasize aesthetic feeling, while banners, or large-scale works, want momentum and require different connotations.
The third is composition, which I personally understand. From the layout point of view, Qifeng protrusion is more powerful and has stronger visual impact than Liefu's works.