Fan Yao was always mentioned as having knowledge of all martial arts under the heavens, and we know that Wuji is a bumbling martial artist that only succeeds because of his huge inner strength and super advanced martial arts that he doesn't really seem to use at their full potential.
When Qingshu was using clawing people to death and FY was about to challenge him, he first asked Wuji for some tips and they did some finger stances. My question is whether it really makes sense for Wuji to be able to instruct FY in overcoming im. His general method of victory is being WAY stronger, way faster, and way more durable than the opponent and having access to higher level martial arts as well.
Does he have the ability to give direction based on Fan Yao's power level and abilities, or at least give better direction than Fan Yao would have thought of himself ? Iirc, he taught him a Taiji move, but I'm not sure how FY would be able to learn and execute such a high level martial art seconds/minutes before the battle. Wuji at this point has still only practiced martial arts for about 2-3 years, and his experience and mindset is still not that of an elite fighter yet.
I imagine Wuji to be an extremely fast 8 foot tall basketball player. He dominates everyone and is without doubt the best player, but he wouldn't be very useful in giving advice on how non super quick 6'10 people should be playing.
Imaginary scenario....
FY: So what would Jiaozhu recommend I do to beat him?
Wuji: Well you can just let him hit you and then repel him with ultra inner strength.
FY: I'm not sure I can do that...
Wuji: Or you could just wait until he attacks first and then copy his move and get there before him.
FY: I'm not that fast...
Wuji: Well you can just divert his claw onto himself with QKDNY.
FY: *sighs* I'm just going to go ask Zhang Zhenren.