Klal Yisrael has unanimously adopted the minhag of performing the simanim on Rosh Hashanah. However, Klal Yisrael as a whole is supposed to keep all the 613 mitzvos, with everyone doing his part. (We also find that Klal Yisrael is compared to a single individual, with every segment representing a different vital organ.) Although as individuals they might be empty, they are nonetheless part of the unity of Klal Yisrael, and therefore they cannot be called truly empty. Together, as one whole — one body with one soul — we should merit to perform all the 613 mitzvos in the coming year.