Because the real history cannot be verified, I just answer the following questions on my personal view of history:

First of all, as Ethan of Tang Gaozu, he was originally the master of a clan. If he was a mediocrity, he would not seize the opportunity in the turmoil and build the foundation of the Tang Dynasty.

Secondly, Cheng Jian, Shimin and Yuanji are all sons of Ethan, and it is very important to cultivate their fathers in ancient times. If he is too ordinary, his son will be ordinary;

Third, there has never been a shortage of military commanders in the long river of history, but there are few wise kings who can run the country well and have a comprehensive view of China's history. There are at most one or two wise kings in each dynasty, and there are countless military commanders. The three countries are good examples;

To sum up, I personally think that Ethan, as the founding king, should have certain abilities.