Well I mean, it's just more direct & quicker, & therefore cheaper to go through Ytsur, providing that Ytsur isn't a bunch of pirates and OTA doesn't go ballistic and overtax because merchants are taking the quick way and goods still go to them.
ETMs are entitled to the same protection and tax rights and restrictions. OTA is not permitted to tax above 10%, and likewise, the New Union cannot tax OTA members or other ETMs of OTA greater than 10%. As is part of the OTA agreement, OTA members and ETMs are to protect each other's trade interests. The only thing that ETMs are not entitled to are district policymaking influence and organizational influence of all of OTA. They may send representatives, but they do not have voting power in meetings. As for the third district (Avalonia, Siderland, Albhad), Albhad has authority on trade protection.
As far as ensuring your traders' safety in Ytsur, there is a travel ban where Albhadi citizens cannot cross Ytsuri borders or cross into Ytsuri waters. Besides the fact that they can gather foreigners as slaves, it is advised to avoid that region as much as possible. And as mentioned before, taxes for traveling through the region are higher. Albhad says that it will refuse protection in such an instance.
Ytsur, however, will agree on the cbrown town if Avalonia pays for 75% of it.
As Teijin forces are drawn in to stabilize the issue, Ezbatan forces rush to the southern wall, and split its forces three ways, with each infantry force fighting any residual opposition force that may remain there after troop relocations. The infantry outnumbers the Teijin forces and manages to get them to retreat to the wall. Double ballistae then begin to fire bolts at the wall, which after a period of time, in the three contact points, manage to breach the wall.
Strange carts full of ceramic pots then roll up near to the wall as crossbowmen and light infantry breach the wall to cause mayhem inside. Soldiers then begin to grab clay pots, light a small fuse at the top and then throw them at any defense points or arrow loops. The pots burst on impact and scatter flaming oil-åkēle-seaweed mixtures all around. This produces noxious black clouds and a great deal of fire, producing the unknown effect of suffocating anyone in enclosed spaces.
At this time, cavalry breaches the wall and rushes in to cause major damage from behind.
Meanwhile, at sea, the united force departs from Xaonaan and is heading in the direction of the enemy fleet, according to numerous patrol reports.