Huns arriving a century earlier

[Silver01]

Recovery might still happen but it’d be slower and Germanic invasions more threatening. Also I suspect (but can’t really prove) the early days of Diocletian’s reign weren’t as stable as chronicles made it seem, given political instability, a horrible economy, and the massive reforms of the time

The goths would be showing up in 270s during Aurelian, while sources exaggerat the Germanic invasions of the third century were just as large if not larger than Adrianople

 

[Silver01]

Because unstable or not they were also in a far better military position. Their armies were larger and not degraded as they were a century later. By the times the Huns became a threat iotl the western empire had been through a catastrophic war with the eastern empire that left it depleted and had been dealing with invading Germanic tribes picking away at the empire. That’s a hell of a lot worse than the late 200s.

Assuming not much butterflies from gothic migration the Romans are in for a bad time if the Huns first major raid is in 295 , I think Diocletian wouldn't retire but assuming the tetarchy fails in early 300 the civil war plus hunnic raids would make the Balkans a dead Zone and I can see a similar destruction if not worse than what Attila did do the area

 

[Gloss]

Because unstable or not they were also in a far better military position. Their armies were larger and not degraded as they were a century later. By the times the Huns became a threat iotl the western empire had been through a catastrophic war with the eastern empire that left it depleted and had been dealing with invading Germanic tribes picking away at the empire. That’s a hell of a lot worse than the late 200s.

I'm not sure what evidence there is that the army degraded by 370 CE compared to 270 CE

had been through a catastrophic war with the eastern empire that left it depleted

Palmyrene Empire - Wikipedia

en.wikipedia.org

Battle of Edessa - Wikipedia

en.wikipedia.org

 

[ImperialxWarlord]

I'm not sure what evidence there is that the army degraded by 370 CE compared to 270 CE

Palmyrene Empire - Wikipedia

en.wikipedia.org

Battle of Edessa - Wikipedia

en.wikipedia.org

So then why was the western army so weak by the time of the germanic migrations and conflicts with the goths and then the Huns? Why was Stilicho so short on men? The Rhine frontier was depleted and unable to prevent the crossings of 406. And why is that all? Because theodosius’s war against the west saw massive casualties for the west. You point how bad things were in the late 200s but forget that the Romans were able to recover and strike back and bring the chaos to an end. The same didn’t happen a century later.

Battle of the Frigidus - Wikipedia

en.m.wikipedia.org

 

[Jürgen]

A aspect people ignore on the Germanic migration are climate, the Germanic migrations were to large extent pushed by climate, so the Huns arriving earlier are unlikely to result in OTL massive migrations, but instead the Rhine are more likely to see Alemannic style push across the border.

 

[Collondi]

The goths would be showing up in 270s during Aurelian, while sources exaggerat the Germanic invasions of the third century were just as large if not larger than Adrianople

The largest invasions of the third century were 30,000 men but these were large coalitions, when Aurelian beat Cannobaudes/Cniva in battle he supposedly killed 5,000 men which was supposed to have been a devastating loss for the king. Though there might have been other factors that lead to the increase like the forming of confederations like Franks, Alemanni, etc. or climate change like @Jürgen pointed out