Workloads that perform multi-deletes and then assert on the number of documents deleted will not work with balancer or migration suites. This is because multi-deletes aren't versioned, and thus do not filter for orphans. During and after migrations, there could exist an undefined number of orphans, due to either:

1. Documents currently streaming to the current node in process of a migration that have not yet been "assigned" to the node via shard versioning, or
2. Documents not yet deleted ("left over") on a node that has officially migrated documents to another node.

The consistent solution is to blacklist these suites from the balancer and migration suites.