Sectarian Groups in Eusebius's Church History Developed From the Latinized -ιανὸς Ending and the ίων Ending

Ἀννιανὸς
Τερτυλλιανὸς
Τατιανός
Χριστιανὸς

Χριστιανοὶ

Citing from Hegesippus's Memoirs:

Σιμωνιανοί
∆οσιθιανοί

καὶ Μαρκιανισταὶ καὶ Καρποκρατιανοὶ καὶ Οὐαλεντινιανοὶ καὶ Βασιλειδιανοὶ καὶ Σατορνιλιανοὶ (4.22.5)

almost the same list appears in Justin Dialogue 35:

καλούμενοι Μαρκιανοί, οἱ δὲ Oὐαλεντινιανοί, οἱ δὲ Βασιλειδιανοί, οἱ δὲ Σατορνιλιανοί

The two early sources must go back to an original syntagma written in Latin. This source explains all the early usage of the Latinized -ιανὸς ending in early Christianity.

Eusebius seems to have consistently corrected the name 'Μαρκιανοί' to read 'Μαρκιανισταὶ' (the chosen Marcionite form of Origen's surviving manuscripts is the closely related Μαρκιωνισταὶ (cf. Against Celsus 5.62 and other sources).

For some of the heresies have a great many martyrs; but surely we shall not on that account agree with them or confess that they hold the truth. And first, indeed, those called Marcionites, from the heresy of Marcion (τῆς Μαρκίωνος αἱρέσεως Μαρκιανισταὶ καλούμενοι), say that they have a multitude of martyrs for Christ; yet they do not confess Christ himself in truth. (5.16.21)

It is worth noting that in some manuscripts Μαρκίωνος reads Μαρκιανός, and Μαρκιανισταὶ is corrected to read Μαρκιωνισταὶ.  This makes the identity of the 'Marcianos' in the surviving Demonstration of the Apostolic Preaching referenced by Eusebius here all the more interesting:

Besides the works and letters of Irenæus which we have mentioned, a certain book of his On Knowledge, written against the Greeks, very concise and remarkably forcible, is extant; and another, which he dedicated to a brother Marcian (, ὃν ἀνατέθεικεν ἀδελφῷ Μαρκιανῷ), In Demonstration of the Apostolic Preaching; and a volume containing various Dissertations (διαλέξεων), in which he mentions the Epistle to the Hebrews and the so-called Wisdom of Solomon, making quotations from them.(5.25.1)

The reference to the heresy at Antioch at the time of Serapion is also worth paying attention to:

But you will learn, brethren, from what has been written to you, that we perceived the nature of the heresy of Marcianos (αἱρέσεως ὁ Μαρκιανός), and that, not understanding what he was saying, he contradicted himself. (6.12.5)

And finally:

Νοουατιανῷ (Νοουάτον)
Κηρινθιανὴν

Φαρισαίων
Ἐβιωναίων
Σμυρναίων
Ἀριστίων
Κελαδίων
Θεοδοτίων
Σεραπίων
Μανιχαίων