The Abandonment of the Gladius for the Spatha - Why?

[Thiudareiks Flavius]

Very interesting subject!

I think another reason is that the "classical" roman fighting with a short sword and a largue scutum needs more training than fighting with a long sword (or a spear) and a oval scutum.

It does? Why? I can't see how that follows at all.

We can think that in the late roman army factours like training and discipline were not so important like in the laterepublican or imperial armies.

The late Roman Army continued to fight in disciplined formations and continued to be a highly effective fighting force right up to the very end of the Western Empire and, in the case of the Eastern Army, well beyond. Sorry, but I can't see why formation fighting with a short sword and rectangular shield would require any more training than formation fighting with a longer sword and an oval one. And I can't see any good evidence of a decline in training, discipline or effectiveness in the later Army.