We'll know for sure when a fish writes a book

However, in the interim, it's obvious it does make a difference given your very own experience recently. You have to think what was different between the methods. List all the possible differences and it's one of those

Which one has to be determined by an elimination process, but there may not be enough evidence to say for definite which one, so we are back to probability and experience to work it out over time. I'm no expert, that's for sure, but obviously the "long leader and leave them alone" approach produces a (very) slowly sinking buzzez....if that's what the fish wanted, then that method was producing it. The addition of the heavy buzzer on the point put your long leader at a distinct angle in the water, thereby fishing different depths more effectively.....it's very possible you could catch more without it by finding the right depth and presenting all three buzzers in that area for longer etc etc....the permutations are many, just keep thing about it....somedays it doesn't matter that much, some days it absolutely essential

Just my humble thoughts on the matter