Again, Islamic culture provided an unifying framework for the cross fertilization of tought. I mean arab was obviously needed for the comprehension of the Quran, hence shcolar from all the islamic world could communicate with each other (Yeah I'm captain obvious). As for the " orthodoxy kicked in" always this phantasm of the pure innocent and progressist truth demolished by obscurantism. Al ghazali , who is usually considered the "bad guy", when criticizing philosophy and logic, did not rejected it , in fact he used it strongly for his jurisprudential work and encouraged strongly medicine and mathematical study, he just stated that reason should not dominate revelation, wich in a muslim point of view he's perfectly coherent.
If it was Islam which provided this impetus, then the Muslim countries with the greatest scholarship & achievements would've been the regions of Saudi & Yemen, the two places which were Islamized right by Muhammad. Obviously they weren't.
The lands where Islam made certain achievements-persia, Mesopotemia, Egypt were all ancient superpowers, they didn't require this Arab faith to suddenly invent, they were doing all this for the last 3500 years before Islam.
Muslims benefitted from conquering these ancient successful lands, took stuff like 0 & decimal positioning from India, slowly as these lands were majority Islamized, around the 16th century, Islamic science died out.
Its like if Islam manages to takeover USA, Europe & Japan today, they'd still be innovating for some years till the pre Islamic ethic lasts-but that won't be due to Islam but for the pre Islamic ethics & ideas, then they'd become Islamized & perhaps as backwards as Saudi & Yemen.Just like Egypt, Persia, Mesopotemia etc.