“I don’t think he’d hold by the science he had in his days (same with Hazal; they were going by what was available they had in their days).”
Correct. In numerous places one can see Chazal’s care in observation. In at least one place (Pesachim 94) they accept that the non-Jewish explanation is better than theirs. Rambam is explicit about this in Guide to the Perplexed III, 14.
Rav Hirsch confirms this; see “The Educational Value of Judaism”, in *Collected Works, Vol. 7*.