Actually ww1 was more balanced than ww2 and it is possible to make relatively balanced and historical great war scenario. The Centrals would have won if Germany had taken Paris regarsless of date. Even If Germany had knocked France out of war in 1918, Allies would sue peace since Normandy style liberating France would be unimaginable. The Allies did even fail to knock out the Ottomans out of war by naval invasion.
Even Italian neutrality could bring Central victory. With Italy, Centrals would achieve definitely total victory.
Another problem is Italy and Romania could have joined the Centrals and hard to represent it in Triplea Engine. But USA would always join Entente regardless of the Zimmerman telegram or unrestricted submarine warfare.
I agree the Ottomans are represented way too strong. But the problem is if you make the Ottmans 1/10 Germany then Entente would take the Ottomans within a few rounds but in reality they would only do it after 4 years with Arab rebels. In this scenario you will have to give thr Ottomans so much defensive bonuses since Gallipoli isn't the only Ottoman victory. Ottomans did win more battles such as First battle of Gaza or battle of Kut etc.
Simply taking the Ottomans should not be too easy realistically.