Over time, the decline of Tyrosh is inevitable. It's current position relies on three factors. First, it's the capital of a major polity, the administrative and cultural center for roughly a third of the people who live in the disputed lands, not to mention the city itself, which has ended. Second, it's trade position as a major port of call along the N-S Narrow sea trade route, arguably better than Myr, or even Pentos given it's relative positioning. In this, it's being supplanted by SD, becoming a mere satellite city. Finally is the actual bedrock of it's economy, its locally produced goods. The resources that wont be directly out-competed is the native snails that they've been cultivating since the freehold. With that in mind, I'm certainly aiming for over-recruitment from the population in anticipation of the economy and city will be smaller in the future (via migration to our other territories).
That being said, I'm not sure if we want to accelerate the migration away from Tyrosh, or slow it down. We'll need a good number to be shunted into our legion/watch efforts to be ready for Lys/Myr/Pentos (reminder that the closer to each other they fall, the easier the conquest will be overall since it avoids anyone hitting a panic button calling in outsiders like Volantis, or Outsiders, like demons or Deep Ones.), and there is ample opportunity for farming, salt mining, and other semi-skilled labor tasks (farming in particular is important) but if we move too many people, too fast, that's just asking for problems (slums, crime, anti-immigrant sentiments, etc). I've not thought too much about it, but we'll have a good deal of control since we control the sea. Always makes controlling immigration/population movement easier.
As for Tyrosh itself, I think repairing it to previous standard will have to suffice for awhile. We'll need to be rushing the improvements on our other holdings or they'll all turn into slums fairly quickly as their population explodes (metaphorically
). SD itself needs housing expansion just to cover our native population at this point, much less our new wave of immigrants we're expecting shortly (though moving the legion to Westhaven from SD will alleviate that enough that putting action towards it next month makes it doable).