Here is a list of legions used against Parthia that I posted some time ago:
"In his biography of Trajan, Julian Bennet mentions that, at the begining of the parthian campaign the roman army was gathered at Satala (south of Trapezunt in Cappadocia)
The army was supposed of being made from some entire legions or parts of legions as follows:
-from Syria - III Galica, IV Scythica, VI Ferrata
- from Cappadocia - XII Fulminata, XVI Flavia Firma (the last was based in Satala)
- Judeea - X Fratensis
- Arabia - III Cyrenaica
From the Danube came, on land across the Balkans and Asia Minor, or on the Black Sea from Tomis to Trapezunt the following:
- in full - I Adiutrix, XV Apollinaris
- probably in part - VII Claudia, XI Claudia, XIII Gemina, II Traiana fortis, XII Primigenia, XXX Ulpia victris, I Italica, V Macedonica.
The total number it's hard to guess, but the author proposes that from this 17 legions were at least 8 full legions with at least as many auxilliaries for a total of some 80. 000 men."
I will look in Bennet for the legions of the Dacian wars.