and all you need to do is to get the distance right.
The "range" in everything I've ever done has always BEEN the distance. Whether in the military on the rifle or artillery range, or at the golf driving range.the targets always have the distance marked on them or known before hand from a topo map or rangefinder on the periscope, for the old navy guys.
In fact, in the military the "distance" is called out as "range" and referred to as "range" (ie. "maximum effective range").
It is the "direction" or "azmuth" that is much easier with an overhead cast because it doesn't change much with line speed variations, height above the target at turnover, loop size at turnover and so on. When the loop straightens out it is going straight down. All you have to do is go straight back and forth with the rod once you have the direction.
With a 45 degree cast it is not coming straight down but on a 45 degree angle. So both loop size, height above the water at turnover, turnover speed are all variables as well as the point it space where the rod tip stops, because that determines the direction the line will go initially.
But for a lot of fishing, accuracy is not that important especially if you haven't a clue where the fish are, if any,.
But there is no doubt that it is much easier, in light wind, to get the direction right with vertical casting.