When host machine attached to existing domain you don't really need third machine running domain controller.

Loopback adapter provides sufficient utility to configure public network for cluster and expose Virtual Instance IP through route built to host external adapter.

An inconvenience is when connecting to SQL Server Instance need to specify port in the connection string ( alternately one could configure an alias on the client )

It would be really nice if Browser service could be installed separately and bound to an IP ( or FQDN ) with Port ( an address as opposed to installed SQL Server Instance ). Would be very helpful in solving above inconvenience.