Impedimentia Nationality

[Ruskolnikov]

Hi

While playing Carrhae I noticed that the Romans can only purchase Egyptian impedimentia
While not a major issue, this struck me as odd as the Romans have the skill to build seige weapons/equipment, and have the manpower to train additional soldiers, but do not have the ability to create their own impedimentia (which presumably are horses, wagons, and crew requiring little training).
Following on from this, it seems odd to me that you would need replacement chits of the correct nationality for impedimentia - is an Egyptian waggon etc so much different to a Roman one?

I would appreciate any thoughts you may have on this

regards

Mark