Problem is, the moment you set constraints on the conflict we will come to the argument of bias. In this case we have two civilisations, neither of which has reached the maximum technology possible to it, or used all its resources, so even if you try to set the time as when the civilisation was atr its most advanced it would be impossible. In human terms, conflict on Earth is not a problem, we are compatible bodies, basing our science on the same principles. What if the ST guys arrived in the SW galaxy, only to find that the SW guys were 20 times bigger than them? It's entirely possible that their technology isn't even backwards compatible, let alone compatible... It all depends on the rules for the conflict that we set, but then we get bias in the equation. It is, in effect, an unanswerable question.