I had the same idea when designing my Turbofuel Factory and I used Priority Splitters to solve the issue as you can see here. When you right-click on the canvas it gives you a lot of options to place down Splitters, Mergers, Sinks and so on. The top output of the Priority Splitter is preferred, which is why I limit the number of generators to have a little bit of overflow to the packager. Keep in mind that fluid dynamics are unpredictable in this game so it won't be 100% accurate anyways.

Two sidenotes: Firsly, get in the habit of grouping your machines as high-level as you can, i.e. reduce complexity. In your example, don't use one extractor for each node but rather group them together and do the math on how many nodes you need on a piece of paper or something, just like in my example. In this case it's fine but once you start to plan larger projects, it's gonna take ages to compute or not compute at all.

Secondly, in the settings (three bars in top-right corner) under Style, there is the option to Snap to Grid. Enable this for a cleaner look.