They seem to really want to trade Cardamine, but they are not too smart, you are right there. Naturally, they won't be able to replace Junkers and we have to work on restoring Rochester as soon as possible.
We sure can go in and punish them as we usually do, but hear me out. This Rochester attack has exposed the problem of our network in Liberty not being too diverse. Xeno people seem to have their own independent network that was not accessible for us before we can use it for diversification of our trade. They also dropped additional message telling that they have a lot of "foreign" slaves for sale on the planet.
I say it's much easier to defeat them with Cardamine and money. They are poor and will become dependent really fast. I see that as easier solution, especially considering that our forces are going to be concentrated on dealing with shit in Taus.