How to recruit Siege Engines as Romani?

[Revenant]

My problem is precisely as stated in title. I play as Romani, now have Polybian era units and can recruit them without problems. But I cannot recruit any siege engines.

I looked into buildings datafile and it looks like they should be available from mid to high level barracks, but none are present...

For example, I have second highest Polybian barrack in Roma and nothing.

Are they available only since certain date? And I met such units in the hands of my enemies.