The more people in the meeting the more targets Bob Muehler has to put the squeeze on to find out on what really went on in that meeting what was promised and what was delivered.  Promising low level (low lifes?) like this real estate dude and the interpreter immunity from prosecution will get them to sing and sing loudly.  Just waiting to find out who in that meeting later on told Donald Sr about the meeting.  We already KNOW Trump is lying about it - we just need to hear it from the canary himself.