In Toronto where there are two sets of parallels
33L/15R 33R/15L
23/05 24R/06L 24L/06R
arrival aircraft don't need to be staggered if they are on a visual approach....ie you can run them in side by side. It does also help if they are visual with each other. It looks worse on radar than it does in reality.
As 120.4 says though the rules do depend on the distance between runways. If the weather does not allow visual approaches you have to stagger aircraft on the approaches...OR use an ILS monitor to ensure aircraft don't wander off the approach.
The most common operation in YYZ is dualling...Land/Depart 23/24R 05/06L
Those runways are greater than 9600 ft apart so the stagger (if not visual) is 2.5nms according to the Manops.
If the stagger is not possible due to volume of traffic all you do is establish aircraft on their respective localisers with vertical separation and then switch to ILS monitor. It allows for a lot of traffic to be shifted!!