Oh, do you know Mr. Huffman? He's a very strict knight, not to mention disciplined. He's never asked for my autograph or tried to make conversation. Every time he comes to the Cathedral on official business, his face is a picture of seriousness.
BARBARA TO THE TRAVELER IN A VERY SPECIAL BEVERAGE

Those who know Huffman have described him to be hardworking and reliable; Paimon once compared his dedicated attitude as a Knight to the looseness of his superior Captain Kaeya.
One of Klee's stories implies that Huffman has been a Knight of Favonius for at least three years, having interacted with Klee's mother, Alice, before she left Mondstadt. He once scolded the both of them, and no doubt that they were causing trouble.
huffman (genshin impact)