You might encounter performance problems if your cluster's hosts have an imbalanced distribution of FT VMs.
Some hosts in the cluster might become overloaded with FT VMs, while other hosts might have unused resources.
vSphere DRS does not load balance FT VMs (unless they are using legacy FT). This limitation might result in a cluster where hosts are unevenly distributed with FT VMs.
Manually rebalance the FT VMs across the cluster by using vSphere vMotion. Generally, the fewer FT VMs that are on a host, the better they perform, due to reduced contention for FT network bandwidth and CPU resources.