Short sighted patricians who are willing to look the other way for a healthy bribe/cut of whatever money they get for facilitating an artisan to go to the Western Ymaryn, who as everyone knows are still People and are related and everything, so it's not like its really a problem, you know?
A patrician might be short sighted, but as I understand it, our guilds are mostly autonomous state agencies who govern the artisan class; and we have no concept of separation of powers. With Greater Justice valuing the group over the individual, what stops the guilds from dealing with the issue internally? Why are the patricians relevant here?
They pretty much have to have that power otherwise the guilds themselves would have been broken long since, as someone would have bribed themselves out to set up rival guilds, and the system would have collapsed due to the introduction of competition.
They also have to be continually and repeatedly short sighted without a short space of time, as the economy should be sophisticated enough now to require division of labour, so a single or even small number of defecting artisans would be completely screwed, as the concentrated urban supply chain they depend on is missing. A porcelain maker wouldn't have the klm maker, or the high quality's charcoal burner, or the glaze maker, or the dye maker. Unless the Western Ymaryn have a True City, they simply shouldn't have the economies of scale to support the division of labour to support these crafts.
Look at what the Bronze Age Collapse was about. Part of it was the inability to support urban civilisation.and the related specialism that enabled urban civilisation. The Western Ymaryn should be in the same boat for a long time, and will be dependent on purchasing from core Ymaryn. If they get vassalised and we turn off the continual support, they should implode in short order.