mjhjmtu

Sorry if this is the wrong place to ask this question, as its very much hypothetical.

In the computer game Kerbal Space Program , there are 3 main Staging Options that are used

1. 
   Conventional Staging where each stage seperates the reveals the engines above it, the same as used in the Saturn V Rocket.


2. 
   Onion Staging where an outer tank feeds into an inner tank and when empty is dropped, similar to the crossfeed between the Shuttle and Main Orange Tank


3. 
   Asparagus Staging where Engines and tanks surround the main rocket, which feed into the rocket beside it around the central core then to the next to the next and then to the central core which above it has the final stage, this setup in KSP allows lifting huge spacecraft into orbit

This means that the Fuel and Oxidizer Tanks in S4 actually feed all 7 Engines, until empty and dropped, then S3 feeds all 5 until empty, the dropped, Same with S2, and then S1 is now already very high in the atmosphere travelling very fast but is basically fully fuelled and continues on into orbit

This is the meat of the question, Aspsargus staging in KSP is easy, just done with magical fuel lines, but in reality, it would take huge pumps and fuel lines and structural supports. so all this added weight would reduce the effective DeltaV you could gain from it. but i'm not sure how much

Now i know that without specific information in terms of Mass of the stages etc its impossible to do the actual Maths, but:

The Question

Is this even realistically possible in real life? or would the drawbacks outweigh the benefits

It's possible, but not as easy in real life as it is in KSP.

To maintain proper tank pressurization, the crossfeeds have to be pump-driven; the fuel and oxidizer crossfeed lines have to be pretty large to move the required amount of propellant (i.e. on the order of the same power as the core section's engine turbopumps). All this increases weight and complexity.

In your proposed design, a minor issue is that the pumping direction of the outer tanks produces a rolling torque on the rocket which has to be countered (via gimbaled engines or other attitude-control mechanisms). No torque is produced by the S2->S1 feeds in your design, so a single-level N-to-1 crossfeed, like Falcon Heavy's proposed 2-to-1, doesn't have to worry about it.

It turns out to be possible to get some of the benefits of asparagus crossfeed by throttling the core engines down while the boosters are running -- the outer tanks thus empty first because they're consuming propellant faster. This is much easier to engineer -- no crossfeed plumbing, just throttlable engines. This is what Falcon Heavy actually does. Installing more or larger engines on the outer boosters would be generally equivalent, as well.