Alright, so if a person trains 27 hours a week with approximately 50 weeks in a year that would mean they would train about 1350 hours a year. They get a black belt in four years so when you multiply 1350 by four you get 5400 so it takes them about 5400 hours to get a black belt.
Now lets say somebody else gets a black belt in ten years which is more or less the average length of time it takes to get a BJJ black belt. Lets say they train five days a week for two hours each day and from time to time they might do an extra day and/or extra hour of training. If you do the math that's about how much a person would have to train to be able to do 5400 hours in ten years.
So, the point is this, in the first example it took a BJJ practitioner 4 years to get a black belt. In the second example it took a BJJ practitioner 10 years to get a black belt. Yes you can say in the first example the practitioner got a black belt sooner than in the second example since 4 years is obviously less than 10 years but the fact remains in both cases it took 5400 hours. Although the practitioner got the black belt sooner in the first example they didn't rush it since they spent just as much time as the practitioner in the second example, 5400 hours. Therefore the practitioner in the first example did not rush it. 5400 hours is 5400 hours whether its spread out over four years or ten years.
Trying to get the same results of 5400 hours of training in say, just 1000 hours that's rushing it. Training for 5400 hours in four years instead of ten is not.