Harsher partition of Ottoman Empire will be result of Ataturk absence. Gallipoli campaign can still be won with even worse commander of 19th division, but Caucasus campaign without him is going to be even more disaster than it was IOTL. It is likely mean less of Armenian Genocide and larger post-war Armenia. I do not believe the Armenian Genocide can be completely averted - the Armenian fledgling state was too deeply corrupt for the organized self-defence. I remember diaries mentioning Armenian army officer selling ammunition to Turkish Army and leading his battalion to pre-agreed massacre location to cover up the stealing.