I am quite sure that the Instanbul- San Stephano figures are correct because it is after all the Ottoman capital it has its permanent garison which is numerous enough. The thought that the Ottomans have all their troops around Edirne and on the Bulgarian border and nothing else seems strange.Also saying that the bulk of the Bulgarian Army 340 000 men was pitted against 115 000 is not the same because the Bulgarian divisions include a number of logistical and administrative personnel that the the Ottoman divisions do not so its like trying to compare apples to oranges.