unbelievable genetics... either you have or you don't.
I agree with you, but his training does have something to with his lagging triceps.
Markus is a super nice guy that just needs to do either close-grip bench press, close-grip floor press or close-grip board presses (he could use a phone book like Branch Warren does/did) to beef up his triceps.
In the last MD with his arms training detailed, Markus hit his triceps with different cable movements and extensions movements, but he does not say anything about any close-grip movements. I think he could easily bring another inch to his arms in a year if he warmed-up with some rope pushdowns, blasted his triceps with 6-8 rep sets of a close-grip movement, and then moved onto his normal routine.
I only suggest this workout as I took it from what Branch Warren said helped him bring up his arms.
BPK