Whats the best way to mirror/duplicate same mouse commands (mouse moves & clicks) from the host PC into multiple guest PC Virtual Machines?
Host PC - windows, Guest PC - windows + through either one - VirtualBox or VMware or hyper-V?

USB over IP/TCP?
Cluster SSH/telnet?
pywin32 script to replicate mouse events over TCP/IP with python sockets library?

Hm, you could possibly do Synergy or Multiplicity to mirror mouse/keyboard.
Would say cluster SSH/Telnet is less efficient for managing multiple VMs simultaneously.

Myself would probably go with syn/multi or if i got time py, as this leaves you with a good amount of control, customization and more.

All down to time you wanna spend + knowledge