You're assuming the other species is non-spacegoing. It seems more likely to me, and at least hypothetically possible, that they've been in space as long or longer than us. And probably if you can bend space enough to make a warp drive, deflecting an incoming piece of matter isn't that hard.
But I agree we're more likely to end up at war with each other.
> It seems more likely to me, and at least hypothetically possible, that they've been in space as long or longer than us.
Statistically, that's a near certainty. In the timeframes of galaxies and evolution, the chances that all the other intelligent species are also just a few hundred years into the industrial revolution is essentially zero.
Yes, rules of cinematic narrative outweight the need to tell a faithful story. I.e. in Stargate universe it would be really boring if the Goa'uld just came, slaughtered everyone and take the rest prisoners for experiments within the first 5min-1hr.
Exept all humanoid life in the modern galaxy was the result of an Ancient experiment, when they seeded their genetic code through a wave traveling through the stargate network. I am not aware of any research on the topic, but I suspect that would scew the odds of humanoid civilizations being at a relativly equal level. Then, it could be argued, that the Goa'uld only get their technological advances from the host species, humans, so they cannot be that far beyond us.
There is of course the (admittedly astonishingly unlikely) chance that we're first. I mean someone has to be the first ones up, and since life on other planets is looking more and more factual other intelligent life should be around and other intellegent life if it was more advanced than us should be MUCH more advanced and we'd see evidence of them changing the galaxy. Since we don't well, maybe we're first.
One thing that doesn't really get brought up enough is the transition from intelligent life to advanced civilization. Due to our sample size, it is impossible for us to even make a rough guess at the odds of a successful transformation from one to the other. It is possible that we are significantly overestimating the odds of intelligent life successfully making the transition.
And keep in mind we are only part way there as well. It is possible that something like climate change (or some other natural/man-made disaster) ends our society before we ever achieve sustainable colonization.
But I agree we're more likely to end up at war with each other.