Oddly enough, though, the variations seem to be impoverished compared to the outputs of well-constrained (lexicalized) grammars.
the combination of the conservativeness and allowance for endless variations defines what I call "bounded productivity/creativity under conservativeness" in natural language production, by which This implies that, on the one hand, productivity of natural language is constrained under strong tendency for conservativeness, and on the other hand, there are endless variations of expressions.