Well Mouraigh1, as the saying goes "it's only the last nanometer that matters" but, this is much too easy to say. Most accidents/incidents come about because of an unforeseen event culminating in a distraction and pilot overload. Sod's law tells us that Sod is always around just waiting for his moment to strike. For the most part poorly applied approaches more often than not do not lead to an accident but that is usually down to fortune: i.e. Sod being pre-occupied elsewhere. If you follow 'Murphy's law Sod won't always be elsewhere. I suggest you take a look at James Reason's 'Swiss Cheese Model'. It is worth a google.
A stable well flown approach will always maximise the cognitive reserve to enable the pilots to deal with the unexpected and thus avoid the slips and errors which are always a major ingredient of accidents.