In terms of brushwork, Yan style is an external brushwork, which belongs to brushwork, while European style is an internal brushwork, which belongs to official law. This is the most fundamental difference of calligraphy, and it also represents two different aesthetic concepts. Yan-style regular script can be said to be the highest realm of regular script. It's hard to learn and easy to use, but you may never learn it well. Moreover, there are many faces of Yan-style regular script, including many pagodas, paintings praised by Mr. Dongfang, Aunt Ma, thrifty tablets, family temple tablets, and god-telling posts, among which one is more prominent. European-style structure is rigorous, brushwork is vigorous, and beginners are extremely difficult. Personally, it is second only to Yu Shinan, but above Liu Gongquan and Chu Suiliang. Because of its single appearance, it is easy to learn. As far as the achievements of running script are concerned, Ou Yangxun can't be compared with Yan Zhenqing. Ou Yangxun and Liu Gongquan themselves are running script masters, but it is a pity that they and Yan Zhenqing were born in the Tang Dynasty almost at the same time, with Wang Xizhi in the top and Yan Zhenqing, Yang Ningshi and Song Sijia in the bottom, and their running scripts were blocked by these mountains.
Since you believe that the strokes of Yan Ti are not accurate, which proves that you can't appreciate the style of Yan Ti, and you think European Ti is easy to use, I suggest you specialize in European Ti. If you want to practice running script, instead of learning from Ou Yangxun, you can learn from Wang Xizhi directly, or learn from Mi Fei and Mi Fei, who are also internal calligraphers, and their achievements are much higher than Ou Yangxun's.