When I think of the Romans I think of LS. People in the middleages forgot alot of stuff also, maybe that is the reason you dont see LS in medevil europe. I think LS and LH are both very good indeed. I think that LS was just cheaper that is why Rome went with it. I mean when i was in the army I learned one thing, Lowest Bidder makes everything. It dosent have to last forver it just has to be cheap and do its job atleast as well as what it is replacing. We can argue LH vs LS all day but in the end it was used by the legionaires because it was good. Ask any U.S. servicemen what he thinks of M16 off the record compared to M14. There are problems and the are good qualties too that is the kind of argument we have here. If EB went to 255AD then they would put it in(I hope they would). But EB just goes to 14AD and for that LH is mighty fine.
p.s.
I love the legion, and Lorica segmenta is my fav but hamata is a very very close second