Could the EB II had the Archimidean Steam cannon units for Syrakousai or Koinon? it can made into reform units such as "Archimidean Reform" and the Prerequisite is built the highest Academic structure in Syrakousai...
The thing is that there is no conclusive evidence that the Syrakousoi or Koinon Hellenon ever even built such a weapon, let alone use it in large enough numbers for it to make a unit in EB II. Unless you can come with conclusive evidence that:

1) This weapon was built and tested
2) Used by armies, in large numbers

this will not be in EB II.