Were Romans really tactially inferior to cavalry?

[Mrbsct]

Hey I been ready a topic about the tactical ability of the Roman army and when the Roman army was at its prime. I hear stories how the Roman cavalry was very inferior in the cavalry of the Sasssanids, Goths and Huns.

How did the Principate cavalry of lets say Trajan and Severus match against the Parthians? Was Rome really lacking behind in cavalry tactics when the Sassanids arose or was it other factors like Rome's weakening? What caused Gordium, Phillip and Valerian to be defeated?
The Sassanids later were sacked by Carus but arose and drove back Julian and Jovian. What went wrong there?

Did Rome really improve its cavalry tactics or just their numbers? What did the reforms of emperor Gallileus do? Also even after these reforms they got slaughtered at Adrianople. Was the Late Roman cav really better than Principate cav? Lets say the Principate army of Trajan met the Huns at Charlons.

[Urselius]

The late army cavalry was certainly more diverse than that of the Principate. Ultra-heavy shock cavalry in the form of cataphracts were more widely used, Dalmatian light cavalry and light horse archers were also adopted and eventually the heavy horse archers also armed with lances of Belisarius were developed.

The quality of cavalry is more dependant on their commanders than is often acknowledged - it has been said that brilliant cavalry generals are born not made. The Romans were not blessed with a great many really outstanding cavalry generals. Aurelian was an effective cavalry leader, but the only great Roman cavalry general of the late period was Constantine I. He used cavalry in at least two major battles, Turin and Adrianople (the battle in 324) as battle winners. The iconography of Constantine's arch in Rome also gives cavalry a very prominent place in his victory at the Milvian Bridge.

[diegis]

Trajan cavalry seem good enough to defeat Sarmatian one, if we take as realistic couple images from the Column. As well he didnt seem to had much troubles against Parthian cavalry
As well, I think Galerius is depicted on a horse when fighting with Sassanids and have cavalry depicted on his Arch of Triumph
As he defeated Sassanids I suppose his cavalry was quite good too.

I suppose that most of late Roman cavalry was however formed from auxiliars or people with a background origin with such experience. Moorish cavalry was extensively used by Trajan for example (and I imagine was quite efficient in Orient deserts as well), and Galerius I think used mostly Thraco-Dacians as cavalrymen (knowing his origins and from where he recruited mostly of his troops).

In my opinion Roman cavalry wasnt that bad, is just that Romans focused much more on infantry and used various auxiliars to cover the "holes" left by their sort of neglected cavalry (as number and even training, compared with infantry legionars)