When you practice regular script to a certain extent, you will form some of your own styles, and then practice running script. At this time, the practice is mastery, not high imitation (for example, you like the pen or structure of this word, just add the advantages of others to yourself when practicing calligraphy), as long as the regular script structure is good, the running script will not be bad!
I don't like Sima Yan and Tian Yingzhang. I guess you don't like clever words. I recommend those with free and easy styles. You can compare them with Xiong Xingnong and decide which one to practice!