Speaking of character development, any take like being as stubborn as a rock like Hugh or as regular as Cheren is A-OK as long as it's believable. Some people simply don't change drastically or is already too well-developed to be convinced to change (think of children who have bumpy lives in their childhood) by nature or due to circumstances, while some people are not as firm in stances and have the space to change or adapt to.
In the end, as long as the character background and development is believable and doesn't end up being an obnoxious Mary Sue/Marty Stu who is always correct regardless if the matter has no "correctness" or even factually against the Sue (unless you are trying to make parodies), it doesn't really matter that much if you want to have incredibly stubborn guys or soft guys. There is no right or wrong in this matter.
In the end, as long as the character background and development is believable and doesn't end up being an obnoxious Mary Sue/Marty Stu who is always correct regardless if the matter has no "correctness" or even factually against the Sue (unless you are trying to make parodies), it doesn't really matter that much if you want to have incredibly stubborn guys or soft guys. There is no right or wrong in this matter.