I think you have my meaning right. But in thinking of non-Adamic humans, ie those not of Adam’s line, the question is what one means by “no hope or prospects of eternal life.” Remember that when Paul uses a phrase something like that, “without God and without hope in the world,” he refers it to Adamic people who have lost God and hope through rebellion and enmity, and are a sad case because they’re out of kilter with their true nature, and because they know it.
Animals, of course, are without such hope or prospects because it would be inappropriate for them to have either the prospects, or the subjective hope. It’s OK for them to be of the perishable creation. We expect the new creation to contain animals, perhaps, but not resurrected animals.
Any conundrum such as you find exists in any scenario consistent with the archaeology and palaeontology, particularly if one accepts evolution. At some stage there is a hominid born the day before the cut-off point between the old, persihable, creation, and God’s plan for a new imperishable one.
And the cut-off point is Adam, not only because, by grace, he is chosen as the firstborn (as Abraham was chosen by grace from all the other people of the world), but because he is made suitable for it - not least, I think, because “God puts eternity in his heart” (to quote Ecclesiastes). And that’s one reason I agree with Joshua’s inclusion of the “special creation of Adam” in GA, at least in some degree.
Perhaps part of the reason for a conundrum is a distinction in the understanding of grace. Many Arminians, thinking of the millions surrounding Abraham, or of the millions not included in Israel, or the billions who have not heard the gospel in the present age, will reason that God will do some kind of quasi-Molinist metric to calculate how they would have responded if God had got his word out more efficiently. Salvation comes not from hearing and faith, but from virtual or “possible” faith - it is a timeless truth, and the real world is, in effect, a sideshow which determines nothing.
In that case, there’s a deep injustice on God’s part in non-Adamites not “having the chance” to have blelssings other than those they were created to have.
But for my part, if grace is undeserved and individual, then it covers the whole of the real creation: it was grace for me to be born a human being, to come in earshot of the gospel, and to respond despite my rebellious nature. I wasn’t given grace to be an apostle, or the virgin Mary, or the King of England - and that’s fine with me.
In the case of GA, we have to ask exactly what we mean by “human,” in the case of Adam, and in the case of non-Adams.