So who trained him?
To me, this boils down to what I call The Hat Theory.
Many superheroes are generalists. They have a suite of superpowers, and no strong focus on any one ability.
But other superheroes are known for one power, and one power only. Martial arts skill, superspeed, strength. And if they don't have a chance to show off that one skill, they end up looking second-rate.
It's for reasons like this that I always rank Iron Fist & Shang-Chi over heroes like Cap and BP. Because that's pretty much all they are good at.
Since Priest, T'Challa's "hat" has been his strategic abilities. His ability to plan for almost any situation.
So having a story hinging on the idea that "he was caught by surprise and didn't have a response" looks worse than it would if we were talking about Namor or Black Bolt.
Especially since EVERYONE seems to be catching him off-guard in his own book.