Shit, man, you need to calm down and stop acting like we're entitled to jack shit. The straight the Trelli are on is the Trelli's land. They can do whatever they want with it, just as we can do whatever we want with our land. Like, do you not realise just how assholeish your stance is? It's completely against anything that could be called justice.
It's nothing more than saying "Those guys have something and I don't have that something, therefore it is morally right for me to take it." Only an asshole would say that. It's wrong. Our Justice value is meant to show that our people realise that you still shouldn't do a bad thing even if that bad thing will give you an advantage. It's grating how you keep trying to throw away all our hard-earned traits which make us morally good, all to make us just like every other civilisation around us, i.e. like assholes. We should not be assholes, regardless of whether it gives us an advantage, regardless of the time period. Our people understand that and so should you.
It's also entirely hypocritical. The Trelli demand that you trade with them to pass through their territory. That's entirely normal! That's how trade works! We, the HK, the Xoh, the Trelli, the Hathatyn, etc., they all have a rule for traders that you trade as you pass through their territory. There's nothing wrong with that. To say that it is just because we are now the ones getting inconvenienced is wrong. If we were the Trelli, we would have every right to demand others trade with us when they pass through our straight. It's hypocrisy, and no, that it's the bronze age and that we gain advantage from hypocrisy are not good reasons to be hypocrites.
Your argument that people acted a certain way in this time period and that we thus should is an especially shit argument that ignores the entire point of this quest. The tag is 'history is in your hands', not 'act like people acted historically'. The whole of the Ymaryn is a testament to how we can and should try to be different from how civilisations normally were in this time period.