I love that the balloons are far too small. Like they didn't understand the elements and buoyancy well enough to know the balloons have to be much larger. Not like we have negative mass particles.
It is complicated. There are several options, each with tradeoffs in functionality, compatible software, and performance.
A simple method is to use one system as a desktop, and SSH into the others as "headless".
Other options include making a K8s or HPC cluster (there are other cluster types).
Spreading a single set of communicating processes requires a low latency interconnect. Something better than Ethernet, like Infiniband. But many programs don't support that.
A person does not need to point out all problems when pointing out one problem.