This is because according to VMware documentation45, VCF supports two architecture models - standard and consolidated. The standard architecture model separates management workloads and user workloads into different domains, while the consolidated architecture model combines them into one domain. For a hybrid model that coexists with VMware on AWS cloud DR solution, the standard architecture model is recommended as it provides workload isolation and mobility across VCF instances6. The minimum requirement for creating a management domain or a VI workload domain is three hosts45.