Battles of Barbalissos and Edessa

[starman2012]

To me the Persian numbers seem quite exaggerated. Of course the Romans downplayed the defeat of Valerian (at least some of them did).

Some omitted mention of it and said Valerian was the victim of mutiny or treachery--which I don't buy.

There surely were Persian incursions after the battle of Edessa. Now according to the Romans Odaenathus gathered some of the Roman troops in the area, the Persians were attacked by a certain Callistus/Ballista as well.

Some Roman troops evidently didn't fight at Edessa or may have extricated themselves. I don't think Callistus had a large force though--IIRC a force transported by ship to an area of Asia Minor under assault. The problem for the Persians was that by then they were spread out plundering, hence vulnerable.

In the meantime Macrianus (a former officer in Valerian's army) had time to lead 30.000 troops (according to the HA) in a revolt against Gallienus.

It does seem like Barbalissos was the worse disaster in terms of losses. There was no immediately subsequent resistance by Roman units, let alone something like Macrianus's force. Not sure btw if the HA is reliable. If Macrianus had 30,000 troops it's a bit surprising he lost at Serdica in 261. By then the central government was in pretty bad shape. He may originally have been in charge of rear echelon, support troops--the imperial anona or some such--as opposed to good combat forces.

To me this sounds like there was quite some confusion after Valerian was captured, on the other hand the loss in the battle itself can't have been all that devastating

There sure were enough prisoners of war to build some impressive things--not just reliefs and a big statue of Sapor but a nice bridge...

as there were still enough troops left to drive back the Persians,

Bit of an exaggeration. The Callistus counterattack frightened Shapur into pulling back, probably because his forces were so attenuated. Odenathus may have got in a punch too but Odenathus didn't do much until 262 CE or after Shapur's army had dispersed.