Continuity mistake: When the soldiers arrive at the city that has been destroyed by the Huns, there are no footprints except for those of the soldiers. But there should be thousands of them left from the Huns ,army, and villagers who battled there. (And this was not because it snowed and covered the prints up. If it had snowed the buildings would be white.)
Continuity mistake: When Shang is talking to Mulan and is asking her name, there is a shot of Mulan and suddenly Shang comes into frame and says "What's your name." There isn't a gold string that's attaching his sword to him. It's also gone in other shots in this scene.
Continuity mistake: When Shan Yu is laughing on the rooftop, there is a shot of the terror-struck crowd. In this shot the dragon the Hun soldiers are hiding under is facing to the left. When they burst out of it, it is facing straight in front of them.
Other mistake: During the song "A Girl Worth Fighting For", Yao has made several excellent snowmen of women. But the army was marching by, and he wouldn't have had nearly enough time to make them.
Continuity mistake: When Mulan has the cricket cage under her dress the amount of cloth that covers the top portion of it changes throughout the whole time it's back there.
Continuity mistake: When Mulan is in with the matchmaker, she starts to pour the tea and spills a bunch of it on the table. A few seconds later she climbs on top of the table to take the tea with the cricket away from the matchmaker. She crawls right onto the tea on the table but has no wet marks or anything on her and the tea is no longer there.
Continuity mistake: In the scene where Mulan throws the tea onto the matchmaker, the matchmaker only has a little bit of blush on that is really light, but then when she has a close up to her face, there is a lot of blush on her cheeks and it is a much brighter pink. This has nothing to do with her being mad because only the blush changes not her whole face color.
Continuity mistake: Mulan throws tea over the Matchmaker to extinguish the fire, but the tea only hits her face, not her backside where the fire is. Nonetheless, the fire is suddenly gone afterwards.
Continuity mistake: In the beginning when Mulan pulls down her sleeve to hide her "Notes" on her arm from her father, she obviously has 3/4 length sleeves, but when she runs down the steps both of her sleeves are down to her wrists.
Continuity mistake: During the final battle scene, Mulan is seen on the roof of the palace, lining up a shot with the rocket. She backs up, and Shan Yu bursts through the roof, leaving a large hole. As Mulan and Shan Yu fight, the hole disappears for a few shots. But later, after Mushu fires the rocket into Shan Yu, Mulan runs off the roof, jumping over the hole, which has reappeared.
Continuity mistake: In the scene where it's raining and Mulan's mother is kneeling on the wet ground next to her husband who has fallen, Mulan's mother starts to stand up. Despite the fact that it's raining and the ground is wet, there isn't any water or wet marks on her clothing.
Continuity mistake: When Shang is telling the troops that they will be picking up every single grain of rice his sword has disappeared.
Other mistake: When Mushu is getting Mulan ready he ties her hair up, but he never makes a knot so how could it hold her hair up?
Deliberate mistake: When the troops are marching towards the village which is now destroyed, they would have noticed it long before they actually do. (The makers did this on purpose so that the song "A Girl We're Fighting For" would end on a good note).
Continuity mistake: When the matchmaker is fighting over the cup of tea with Mulan and Mulan loses grip, the tea splashes on the matchmaker's face and no ink on her face comes off yet when Mulan throws the tea from the tea pot on her face it all runs down her face.
Continuity mistake: Ling's armor changes from yellow to a brown-yellow color at the festival towards the end before he puts on the dress.
Continuity mistake: Throughout the whole time when Mulan is dressed up in the beginning she never has a knot, bow or laces that should be there given the length that was tied around her waist.
Continuity mistake: Khan, Mulan's war horse, starts out in the film as having a pink mouth on a white muzzle. The pink lips are not always drawn in, and during the rest of the film he mainly has a white mouth.
Continuity mistake: When they are singing 'A girl worth fighting for' look closely at the their chest plates. They change colour from time to time.
Continuity mistake: When Mulan is being rescued during the avalanche, they shoot an arrow and Yau grabs the arrow with the point down. The next shot, he is holding the pointed end.
Answer: For the reasons stated. He believes him to be a highly competent soldier and trainer. While this opinion is probably influenced by Li Shang being his son, it does prove to be correct, as Li Shang's training is what allows the small group to succeed in battling the Huns.