But command is "stuff."
Command (not control, which is more the willingness to throw strikes) is an attribute just like velocity, in fact, I'd say looking at prospect history that it's easier to coach up velocity (weight training, etc., improved mechanics) than command. Command, like the ability of hitters to see pitches, is probably more innate and a product of body control/properception.
The ability to paint the corners is a tangible skill, no different than throwing a 4 seamer with velocity and spin.
Deception is trickier, if it was easy to coach, all pitchers would be deceptive, but it seems to be limited to a select few. It may be similar to command in that mastering a deceptive delivery means the body control to master mechanics that are too awkward for most pitchers.
Same with the ability to throw all your pitches from the same slot with the same arm speed, if it was easy, all pitchers would do so. Again, it may be a product of body control/coordination, being able to repeat mechanics perfectly.