We've taken on a hybrid plan for our datastores, a mix between the unlimited VMs per DS and specific DS for high IO VMs.
What we did was leverage our VMware Ent+ license level with datastore clusters and then broke them out to OS, DA, DB, LG-NC clusters of several DS each. OS for C drive, OS partitions and so on. DA for data partitions, D drives, etc. DB for database and high IO drives. LG-NC for logs and non-cache drives such as backups and so on. We just allow for storage DRS to handle IO or latency issues as they arise. We are alerted and we can take action if the issue lingers for a prolonged period. Short anomalies aren't much of a concern.
If there are specific machines that require unique settings we can create those datastores and apply whatever we need there.