Live drilling is a little different than what we consider sparring. Sparring we go about 75% and always move through positions. Live Drilling is something I picked up when Reggie Wright was one of my coaches at IU. I thought they were miserable and would always prefer wrestling live, hence why we now incorporate them.
You should be finishing at match speed but instead of simply cutting your opponent the guy getting takedown has to roll over and stand up. Same guy does takedowns the entire time. We usually go :30, 1:00, 1:30, 2:00, 1:30, 1:00, :30. The intensity is often dictated by how quickly the guy getting takedown gets up.
Once one guy goes it is the other guys turn. We will do it where 1 guy does the entire pyramid then the other guy or where we alternate and each guy does the time.
I hope this helps. It gives the feeling and conditioning of match speed but is also way lower risk of injury.