NAT already obscures the existence of additional hosts running on the same machine, so that may already achieve your goal.
If you use NAT and want to add SOCKS5, just configure your guests to use SOCKS5 to access the Internet.
However, if you want to add guest-transparent SOCKS5 (no per-guest configuration), you'd need to set up a gateway that implements SOCKS5 inside a guest only network to provide other guests with SOCKS5 service.
VMware doesn't support proxies, so you need to provide a gateway to your virtual machines that does. The gateway would be another virtual machine running router software (PFSense, VyOS, etc.). The gateway VM would have two network interfaces. One bridges or NATs to the LAN and is the gateway's WAN interface. The other is connected to a virtual network and is the gateway's LAN interface. The virtual network has all the other guest machines bridged to it.
You would need to configure the gateway based on what you need SOCKS5 for and which gateway you use.