I don't often speculate on cosmeric lore but a thought came to me. We know (see WoB below) that the shattering did not have to happen in the precise way that we think of it having gone. We also know that numerology while a part of the comere and shard lore is not necessarily specific for every shard (see WoB below). While we don't know why this is the case I have a theory. Perhaps the numbers of specific shards relate to the different ways that the shattering might in theory have happened. To develop this perhaps as a result of the shattering these possible futures did not just go away. They stuck to quite possibly the shards who could have differently influenced the outcome.