What you're talking about, Perotin, is 'sewing machine' music. Telemann is a good example. I think Vivaldi too. Even the 'greats' did lots of rehash - Handel, Mozart even J.S. Bach. The Baroque and Classical Eras did have many conventions that where more or less adhered to. Of course, these composers did move away from these conventions in a good deal of their works, and I think that's what makes them great. Not some obscure trio sonata or something that's same to a dozen or more others they did, but its their unique works that make them stand out from the many composers from back then who where (is it fair to say) lesser lights of their era.
Let's face it, much of the stuff from back then does sound the same, basically because it is, in terms of the conventions. They used these same kind of chord progressions in many of their works. Of course we can offer examples like Rebel's
Les Elements or stuff like the sturm und drang symphonies of Haydn, C.P.E. Bach and Mozart as being uber dissonant for the time, but they are not typical of their output as a whole (& I think Wolfie did only sturm und drang symphony, the 25th in G minor, and its one of his most popular works - along with the 40th in G minor - simply because it stands out from most of his other symphonies as different and unique).
There's obvious things like this that's not said on this forum, maybe to protect people from being discomfited (as I recently and periodically get abused by a 'trio' of members here who I've singled out many times) or maybe cos its like treading on eggshells. But read even the most basic books on classical music, and it does describe this type of 'sewing machine' music or 'music made to order.'
Music made to order