If you are using ESXi hosts that have mixed hardware vendors, the VCF 9.0 Installer will throw the following error as shown in the screenshot below:
ESX Hosts don't have the same vendor. vLCM is not supported on ESX Hosts with different vendor. Found vendors are: [micro computer (hk) tech limited. gmktec]
The reason as outlined is that vSphere Lifecycle Manager (vLCM) does not support heterogeneous hardware vendors when it attempts to construct the vLCM Image Profile for the vSphere Cluster that is for your VCF Management Domain.
With that said, for lab purposes there is a workaround ...
In fact, this was something I had shared a while back which is the ability to simulate custom ESXi SMBIOS strings and I just recalled the solution because I wanted to test something out but unfourntately, my ESXi hosts were from two different hardware vendors.