Anyway, on the matter of non-original inventions: the Roman contribution is in no way diminished by the fact they weren't the original inventors. For example: one cannot deny that the US, Japan and countries around the world gave a very large contribution to the automobile industry in no way makes it smaller just for the fact that they did not invent the original Daimler Benz engine in the XIX century (in Germany). A great part of the Roman greatness comes from spreading Classical Greek culture and original ideas they adopted to very large proportions, such as the spatha designs (which influenced pretty much a lot of medieval swords, and was based on a previous Celtic one), chain mail (idem), aqueducts, their writing (which was based on the Etruscan one, that was based on Greek, which in turn came from the Phoenician alphabet) and etc...

So, regardless of fanboyism, Roman contributions were also great in their own way ;).