This isn't rocket science. If fish dominated the early devonian and the late devonian is dominated by tetrapods, then it should follow that if evolution is true in that amphibians evolved from fish, then the first evidence of tetrapodomorph life, should be in the mid devonian.
That's why tiktaalik which has fish and tetrapod traits, is in the mid devonian. That is also why the Polish tracks are in the mid devonian too, because this is the time that these animals first evolved and walked on land.
Whether the very first population evolved at 385 or 390 million years ago is irrelevant to the question of whether or not evolution predicts such things to exist where they have been found . Large transitions from fish to amphibian to reptile to mammal take some 100 million years. So to debate over if the first tetrapodomorph existed at 385 or 390 is meaningless.
If evolution were not true, we might find something like a reptile (or mammal or bird) in the mid devonian. The theory would collapse if such a thing existed because reptiles evolved from amphibians and therefore could not have existed before or along side the first terapods like tiktaalik.
Or if we found tetrapodomorph tracks anywhere in the hadean, archean, proterozoic, ediacaran, Cambrian, ordovician or silurian, or if we found the first tetrapodomorph tracks beyond the late devonian, this too would be an issue because it would show us that tetrapods evolved after reptiles which is the complete opposite of what the theory predicts. Or it would show us that tetrapodomorph evolved before fish or along side then, which also would contradict the theory.
But when you point out tetrapodomorph tracks in the mid devonian, all you're doing is confirming the theory. You have 4.56 billion years of rock, so to argue between the ideas that tetrapodomorphs evolved at 385 or 390 million years ago, is pointless because in the grand scheme of things, it's geologically at the same time. It's like arguing if the sky is baby blue or light blue. Doesn't matter it's the same thing
@inquiring mind and if you aren't familiar with the geologic timescale, then Google it