Papadogiannakis, Yannis. 2013. Christianity and Hellenism in the Fifth-Century Greek East: Theodoret's Apologetics against the Greeks in Context. Hellenic Studies Series 49. Washington, DC: Center for Hellenic Studies. http://nrs.harvard.edu/urn-3:hul.ebook:CHS_PapadogiannakisY.Christianity_and_Hellenism.2013.
Chapter 2. God, Gods, Angels, Heroes, and Demons: Parallel Notions of the Intermediaries
Question 158 in the Quaestiones et Responsiones ad Orthodoxos deals with a similar issue.  This objection gives Theodoret occasion to provide instruction on the nature, role, and importance of angels: