Does the piping lenght matter and can it be optimized?

Hi everyone. I'm trying to make a chair factory; and I want it to have no waste, no clogging, no surplus. Basically everything that gets produced (like iron ore getting melted then transformed into nails) is used without any waste. I came across this issue recently: If I want every liquid iron items that come out of my 5 furnaces to meet at the same point at the same exact time, do I need to make it so their piping is the exact lenght as well (What I'm doing currently is making sure every furnace output goes through about 16 individual pipes before combining with the rest of the outputs) ? If so, how does that work exactly? I do know that items going through a longer path will take more time to reach the end, I tried myself and a path that is like 300 medium pipes long will take over 10s to reach the end. I retried the same experiment with the same exact lenght between the first setup that's at the left and the one in the middle (check the second pic); and it took almost twice the time the middle setup took for the water I pumped through the first setup (the one at the left) to reach the end. However, the setup on the right took almost the exact same time as the one in the middle. What does that prove exactly? That lenght isn't measured in the amount of individual pipes but rather in the actual lenght (like in studs) it takes? How exactly is "transfer" speed calculated? Is there even a way to optimize this or should I just opt for a more aesthetically pleasing piping and just connect everything to the ingot molder directly without worrying about the rest? Thanks!

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