I have an update heavy use case where each record gets updated multiple times every minute. There will only be several million documents with each of size less than 4KB. Also the rate at which the documents in each index gets updated is not consistent. One index can have much more updates than another index. In such scenarios is it better to have one index with enough shards (say like 1 index with 50 shards) vs multiple indexes with lesser number of shards (50 indexes with 2 shards each).