Just going to copy and paste this from my response in another thread of why autofill is not an option
Let me make this very simple for you. You have a production line with just 2 stations (keep in mind its 5 stations for a LoL team). Station 1 produces 10 units per minute. These units get moved down the line to station 2. However, Station 2 is only capable of producing 8 units per minute. So the 10 units arrive from Station 1 and after a minute station 2 gets through the 8 units then the next batch of 10 shows up from Station 1. This is an issue because Station 2 still has 2 units they didn't get to. Now there are 12 units waiting to be produced, two more than last minute. Another minute goes by and station 2 gets though 8 more units before the next 10 show up from station 1. Now there are 14 units waiting for station two, or four more than the original. Next minute there are 6 more. Then 8 more. Then 10, 12, 14, etc more. This process repeats indefinitely until there are thousands of units being bottlenecked by station 2.
Now how do you fix this? Well you simply take some of your workers from station 1 and put them in station 2. Now both stations produce 9 units per minute and everything runs perfectly. This is exactly what autofill is. This is exactly why IT ISN'T AN OPTION. Queue times will literally increase INDEFINITELY for every role except the least played one. Not just 5 minutes. Not just 10 minutes. INDEFINITELY. Without autofill, literally the single limiting factor on queue times will be how long it takes for the people at the front to get sick of waiting and leave queue.