I interpret the Reg as requiring the two qualified workers to play redundant rather than separate roles. In other words, both do the same thing. Here are some Guidelines from WorkSafeBC: file:///C:/Users/glenn/Downloads/lockout-pdf-en.pdf (scroll down to p. 26)
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In a group lockout procedure, instead of each worker putting a personal lock on each energy-isolating device, two qualified workers lock the devices. Their keys are then placed in a key-securing system — for example, a box that can be locked or that can have a seal placed on it. If it has a seal, it must be an approved positive sealing device that cannot be tampered with.
A “qualified” worker means one who is knowledgeable about the work, the hazards involved, and the means to control the hazards, by reason of education, training, experience, or a combination of those. The two qualified workers are responsible for doing the following: • Independently lock out the energy-isolating devices. • Secure the keys for the personal locks that were used to lock out those devices. This is done by having each of the two qualified workers apply a personal lock on the key-securing system or by using another approved positive sealing device. • Complete, sign, and post a checklist that identifies the machinery or equipment components covered by the lockout.
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Me again. Note the word INDEPENDENTLY in the second para. This interpretation is reinforced by the Examples that follow:

Example: Group lockout
In this example, a company needs to lock out a piece of equipment with 50 energy sources that’s used by 20 workers. Without a group lockout procedure, the company would need 1000 personal locks to lock out this equipment.
20 workers x 50 energy-isolating devices = 1000 locks
A group lockout procedure can use as few as 120 locks.
1. Two qualified workers each take 50 locks and a checklist for the equipment components covered by the lockout. Each worker places one lock on each of the 50 energy-isolating devices. As they go along, they verify that each device has isolated the energy source, and they check off each component on the checklist.
2 qualified workers x 50 locks = 100 locks
The locks used by the first worker can all be keyed to the same key and the locks used by the second worker to a different key; in this way, only two keys are used.
2. After locking out all 50 energy-isolating devices and testing the lockout, the qualified workers place the keys for the locks in a key-securing system. Both qualified workers sign the checklist and post it by the key-securing system.
3. The two qualified workers each place a personal lock on the key-securing system or, alternatively, they use a positive sealing device, which will have to be broken to get into the key-securing system. The positive sealing device must have a serial number, which the qualified workers record on the checklist.
4. Each worker who works on the locked-out equipment marked on the checklist checks to make sure the serial number on the positive sealing device matches the serial number on the checklist (if the sealing device is used instead of two personal locks). Then each worker places a personal lock on the key-securing system.
20 workers x 1 lock = 20 locks
In this example, a total of 120 locks was used.
2 qualified workers x 50 locks = 100 locks 20 workers x 1 lock = 20 locks Total = 120 locks
For this total, the positive sealing device was used. If the two qualified workers instead each place a personal lock on the key-securing system, then 122 locks are needed.
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I hope this provides the clarification you were looking for. Glenn