I think very difficult for athletes having many years on track to think of 2:03 at the first attempt. Also with a right training for Marathon, they need time for changing their way of fuelling, reducing the consumption of glycogen at Marathon pace. If Bekele (who is in any case faster than Leonard Komon in every distance) was able running 2:05 in his first Marathon, honestly I don't think Komon can run under 2:04, may be a little under 2:05 (but I more think between 2:05 and 2:06) in Eindhoven, which as course is faster than Berlin and Amsterdam.
The situation of Komon is similar the situation of Sammy Kitwara : of sure great talents, great technique, great aggressiveness, but never with the right autonomy for 42 kms, such as athletes NEVER developing long part of career on track, using a lot of lactic tests.
Athletes directly starting with modern Marathon training (Kimetto, Wilson Kipsang, Geoffrey Mutai, Emmanuel Mutai) built an engine able to work at Marathon pace with little glycogen, Optimizing the process of fatty acids. Athletes coming from long career on trck have difficults to do this (tho only ecception is Eliud Kipchoge).