They just
keep on coming!
I already killed a few, and some keep moving out from fog of war... And to top it off, I'm quite certain it was only
one scout that saw me. (one warrior already perished by the way; I thought the scout was from the encampment I was clearing out, so I was a bit late to the defense)
EDIT: It is now turn 83. I destroyed an encampment, plus a second one that I don't believe had anything to do with this invasion, and behind that first encampment there's more land, from which
more keep coming. I think that, around now, I have killed some 15 warriors, 4 slingers, an archer and a swordsman (and two scouts). I lost two units, and have several units that now have two promotion levels (iirc exp after first lvl was reduced in normal game, but my mod has removed that)
EDIT2: It is now turn 98. I am still fighting the same frontline as I did fifteen turns ago. I have killed several Swordsmen as well as another scout, despite not even having researched Iron Working yet myself. On top of that, I lost a Warrior to a Quadririme that appeared from the fog of war when the warrior was moving back to my borders to heal. Also note that I know for certain no scout has visited my cities for the last 40 or so turns.
I really think I should scale the difficulty level back to Emperor and start again...
EDIT3: Turn 100. Two more Swordsmen appeared. I'm done, back to Emperor.