Evolution of Roman Weaponry

I'm curious if any of our distinguished EB historians out there know as to why the Romans changed their weaponry later on in history from the shorter gladius/scutum kit to the longer spatha/ovular scutum kit. Could it be because the spatha was deadlier than the gladius (represented in-game with a lower lethality rating than the longsword)? Or was it along the lines of military reforms based on new non-Roman population integrated into the system who had martial traditions of their own (i.e. with a longsword)?

Also what about the transition from heavy pila to lighter javelins and even lead darts as portrayed in BI for the Roman factions (a bit outside of the EB timeline)? Thanks so much for your time!

adaption of new tactics and changing situations on the battlefield. for example scutum and gladius are nice when fighting in big formations but most of the fighting was going on on smaller scales against raiding parties or like smaller skirmishes. So oval shield and spatha (or semi spatha allowas for both).

it was "in" for some time to link the change in equipment to the "barbarisation". this is not true as it worked the other way around. germanic sword designs were heavily influenced by Roman customs. The Spatha is a Roman design (the ring pommels are Sarmatian btw).

there were several threads about this here already maybe use the search function.

I don't want to dumb down the discussion but...

I've seen a lot of information in this forum about weapon design and performance in a documented or theological sense [ie. sword vs spear vs sharp stick, and all sundry fellow travelers]. However there has been very little here about the availability of raw materials; extraction, processing methods, and finished grads; as well as end item production technologies, costs, and capabilities. All these factors figured greatly into what could in theory be designed as to function, and what would in reality be made and used.

Thanks for the replies. I've done some searching on the forums myself, but haven't seen too much that relates directly to the evolution. From what I have gathered, some of it had to do with differing demographics of soldiers -shifting from Romans to Romanized peoples and the nature of battles from large open battlefields fought in formations to smaller skirmishes as Cinna explained. One common theme is the constant exchange of technologies amongst peoples of the ancient world.

Well, the Spatha first developed as a cavalry weapon, blending the "cheap 'n cheerful" Gladius shape with the reach and weight of Celtic blades. Around the mid second century AD it begins to be seriously taken up by the infantry but this is long after the incorperation of "barbarians" into the legions.

At the end of the day we're not quite sure what happened to cause the change, one possibility is cavalry increasingly having to serve as mounted infantry in a pinch, another is increasing lack of unit cohesion which required greater individual effort, or it may just be the fact that running a man through with a Spatha is no more difficult than the same move with a Gladius.

There's a bit of blurring in which class some swords fall into, after all.