After reading some of your asks and thinking a bit more about the Iskroot got me wondering, how badly would everything go off the rails for the Empire if the Iskroot came to Earth before the Yeerks did?
Hah, I mean, I don’t exactly see a reason why the Iskoort would have gone to Earth at all, since they’re not a space empire. Garzh (which is what I call their planet in Dæmorphing since it doesn’t have a name in canon) is a trade center, much like Venice during the Renaissance, or like Singapore is today. Their status as a trade hub is enhanced by the Yoort, who are the ultimate translators and chameleons, able to broker deals between different people because they have direct experience with so many different minds. People go to Garzh to trade; the Iskoort don’t have much reason to go anywhere else.
The other reason I have a hard time imagining the Iskoort getting to Earth before the Yeerk Empire is because of the Andalites. It is implied, though never stated, that the Andalites exert a great deal of control over who passes through this particular sector of the galaxy.
In The Andalite Chronicles, Elfangor meets Loren because the StarSword stops and boards the Skrit Na ship that kidnapped her and Chapman. Now we’re seeing all this from Elfangor’s perspective so he never stops to question it, but as readers, let’s take a look at this and ask: what right do the Andalites have to board a Skrit Na ship? What the hell gave them that authority? Why is it their business what a random ship passing through our solar system is doing there? The answer is that the Andalites made it their business, whether the Skrit Na liked it or not. Also: what the hell were the Andalites doing on the Yeerk and Hork-Bajir homeworlds? They definitely didn’t ask either of those species for permission to just up and build a base on their planets. Conclusion: the Andalites have decided unilaterally that they are the Official Space Police for our sector of the galaxy (much like the United States has decided unilaterally that it is the Official World Police for Freedom.)
Ax believes that the Andalites fight the Yeerks because of their collective guilt for giving Yeerks technology, but the truth is that the Andalites were active military interventionists in affairs that had nothing to do with them before the Yeerk Empire ever got started. So I think if some kind of exploratory Iskoort mission ever got to our solar system, the Andalites probably would have stuck their hooves into that business before humans ever got wind of it. And that probably would have gone horribly badly, knowing Andalites. They would hate knowing there was some society out there that was more advanced than theirs and accepted all kinds of species and ways of life.