Think of this as three hard efforts of Rowing/Squatting with plenty of rest in between. Because of the amount of rest built in for each round, you should aim to do each row very close to a 100% effort. The set of Squats starts when they pick the Barbell off the ground and ends when you drop it. You can rest as needed with the Barbell in the rack position, but relying on this a lot only to get a few more reps will fatigue you quicker and waste time. Aim to keep moving as fast as possible for one big set and then towards the end you can resort to pausing.