Outside trading; like trading ships too coastal cities, and caravans from outside the map to eastern cities. This could also be used to offset any resource//income issues within the game without a direct cheat/cash injection everyso often.
Higher tier Tournaments; you start off with low tier tournaments, making a name for yourself, as you win you gain access to better (more difficult) tournaments, maybe these could be specialised in certain "Capital" cities, that have a real Colosseum, of which you'd only gain access too by winning low-end tournaments around Calradia.
With that i would also like actual Gladiators, those purely for the arena and not just a bunch of picked recruits from the local army. In these higher ttier tournaments both weapons and armour could be chosen for you, and you could be up against 2-3 Gladiators at a time.
Wanderers from outside Calradia; Just as the name suggest, you have the base for it already.
I has a few more ideas, but i'm having a brain-fart moment so i'll be back