1. The marian reforms require a new MIC complex to be built. The old polybian MICs are damaged so that you can't build the outdated polybain units any more that should disappear.

3. because in the first century BC Roman citizen cavalry does not longer appear as a distinct fighting force on the battlefield. The cavalry in roman armies of the late republic was almost exclusively irregular auxiliaries provided by allied/client states, tribes and contigents enrolled in roman provinces.

4. This is the Equites Singulres unit which is still in EB 0.81a V2. Originally they were planned as early imperial late bodyguards, but since we can't swicht generals guards late enough in the campaign, together with the fact that a whole huge unit dressed like officers isn't really appropriate in any way, they are only available in custom battles*. In future this model will be replaced by an Ala reskin, if we have still need for them.