Im not sure why LS isnt in EB1, but instead heavy armoured irish assault units... ;)
Just kidding, but my goodness, we know nothing about the british island in 270bc, next to nothing about the sweboz and sauromatae and as far as I know most relicts found in Arabia are younger than 200bc.
Still there are a lot of units for all of these factions, which are just possibilities of what warriors at that time might have looked like. If lorica segmentata was used 9ad it was probably used earlier too.
Anyway when the Team says its not in EBII than no point of arguing any further and I guess romans will have enough cool units so nobody will miss LS.