Fastrack and RAP don't impact the total throughput though. If the thoughput is for example 976pph and there is a queue time of 60 mins, then 70-75% of those 976 people will be in the main queue and the rest in RAP and fastrack. When the park estimate queue times they will take into consideration the amount of people in all the queues not just the main queue. So if there's 800 main queue, 100 RAP and 76 Fastrack that's 976 people, which means it'll take an hour to get through that number of people
That doesn’t make the
main queue contain 976 people, though, which is what the queue time given on the app estimates. If the main queue is listed as 1 hour long and the ride as a whole is getting 976pph as its throughput, the main queue will not necessarily have anywhere near 976 people in it. The queue time estimate on the app does not care about Fastrack or RAP or the throughput of the
overall ride; it purely cares about the main queue throughput relative to the amount of people in the main queue.
I’ve previously seen, with my own eyes, instances where the main queue gets as little as 1/3 of the overall throughput at Alton Towers. In this instance, the ride in question was Spinball Whizzer, which was overall attaining about 600pph. By your logic, an hour-long queue would have contained 600 people, but in reality, it would only have contained around 200 people due to only 1/3 of total throughput going towards the main queue.
I’m not saying that Smiler is necessarily that extreme in how much or little throughput it allocates towards the main queue, but my point is more that at Alton Towers, you can’t accurately estimate the number of people in the main queue using such a blunt formula. At a place like Europa Park, where Fastrack is non-existent and RAP is very limited, you probably could take a fair stab at it using that formula, but at Alton Towers, Fastrack and RAP will take a not insignificant, and often wildly variable, share of the overall ride throughput, so you can’t reliably estimate the number of people in the queue based on the hourly throughput alone.