The size of the "tagma" of the Excubitors and its subdivisions can not be determined with certainty; as with the other "tagmata", scholars are of differing opinions regarding its numerical strength. Drawing on the lists of officers and accounts of Arab geographers Ibn Khordadbeh and Qudamah, historian Warren Treadgold suggested an establishment strength of men, which for the "Scholae" and the Excubitors rose to with the division of the regiments in the mid-10th century. Other scholars, most prominently John Haldon, have provided estimates to some 1,000 men for each "tagma". For security reasons, both the "Scholae" and the Excubitors were scattered in garrisons in Thrace and Bithynia rather than being stationed within Constantinople, making it harder for them to be used in mounting a coup.