Curious difference between Pedites Extraordinarii and Samnite Heavy Infantry

These units seem to share the same model. However, the Extraordinarii are depicted as having a full bronze cuirass, with the Samnites having only their typical partial armour. Yet the latter has one more point in missile attack and greater armour and shield value, while being basically identical in cost to the PE. Is this really intended? It seems to me that the PE should be better given that they are supposedly picked troops. Also, it is strange that these almost indentical units are both provided by the roman factional MIC. It would make more sense if PE were factional and the Samnite units were from local MIC.

It's intended that all italic regionals available to the romani can only be trained in the factional MIC. So they can disappear in later reform eras to simulate that continous roman rule has changed italian society.

For the other questions you have to wait until one of the stat guys replies.

I was also wondering why Samnites had such a crazy high armour value of 18.