There don't seem to be enough German Generals with the ability to command Ottoman armies. Generals Hans von Seeckt (Chief of Staff of the Ottoman Army), Liman von Sanders (Cdr 5th Army), Kress von Kressenstein (Cdr 8th Army) and Erich von Falkenhayn (Cdr Army Group F) all come to mind. Allow some German officers (probably not limited to the above named officers) to command Ottoman Armies with no reduction in command rating. Not to forget that German Admiral Souchon commanded the Ottoman Navy as well.
Also every Ottoman Army had a German staff/advisor component. It seems that the way to simulate the positive affect of these advisors would be to increase the command rating of Ottoman stacks which include a German officer.
I have not been able to find the Ottoman General Ahmed Cemal. He does not start the game in Damascus where he commanded from November 1914 and, along with Von Kressenstein as an advisor, raided into Egypt. I should add that his force included pontoon bridges built in Germany. Since these were smuggled through Bulgaria to him and the game doesn't allow smuggling I suggest that the force starting the game in Damascus have a pontoon unit included in its force structure.
With German engineers the Ottomans built a railway from Jaffa to Beersheba to support their advance into Egypt - in is not included as a potential RR build on the current map.