Yes, one delayed aircraft can affect all the 747 routes. Remember, you cannot do YVR-TPE-YVR within 24 hours, so you cannot dedicate just one aircraft to this route.
When the inbound arrives from TPE, it is already too late to operate the outbound. That means that the inbound from NRT or from HKG has to turn into YVR-TPE, and the inbound from TPE has to turn into the other.
If you get one late aircraft, you can upset the entire system, because those aircraft are now never on the ground for more than a couple of hours.
Your only hope to recover would be to substitute a 767 on YVR-NRT-YVR one day, but the loss of load would be hard to schedule in. You might get away with it on a day with a lot of YYZ and east originating traffic which could be moved over to AC.
It is extremely tight aircraft utilization.