Squeak, we have a rare instance in which you and I can publically agree. (See what I mean by the unifying effect of Birchat Hachama?) Indeed Birchat Hachama is an opportunity proclaim that seemingly coincidental “non-events” like the alignment of the sun with other planets at a particualr point in the calendar are also guided by G-d. I was referring to the opinion of many poskim that this bracha is best said “b’rov am.”
As regards your assertion that Chazal used one set of calculations for calculations done by Beth Din and another for calculations done by the laity, please explain then why Hillel Hakatan [seemingly]relied on Shmuels Astronomy and not that of R. Ada b. Shmuel when formulating this calendar? Hillel compensated for the built in error by implmenting a thirteen month year seven times in a nineteen ear cycle. But we know that eventually even that compensation will cease to be effective. R. Ada’s calculations would have obviated the need for the leap year, and would not fall apart eventually.