Simple means that there's less things to break. This isn't just academic. My experience with clusters is that the clustering itself causes more problems than it solves.
(Don't think this is somehow isolated to Windows. ZooKeeper will refuse to start after a power outage for no discernible reason. Etc...)
There's also a whole slew of failure modes that are capable of bringing down entire clusters if a single machine misbehaves. Usually to do with situations where the nodes are reachable, but some resource (I/O, latency, bandwidth) is uncharacteristically slow on one of the machines. I'm yet to encounter a distributed system that handles that situation well
The problem is that the two engines of an airplane aren’t independent of each other in the factors that threaten an engine. Same pilot, same fuel. Separate mechanical parts, but that’s a minority of issues.
Most engine-outs in small airplanes are caused by running out of fuel. Your two engines don’t help you there. If anything it’s more likely because of mismanaging the complex fuel system.
The most common phase for loss of an engine is on take off (misfueled, mechanical issue). This is what your comment reminded me of. With two engines, you’re more likely to have a mechanical issue on take off. While it’s generally theoretically survivable, handling one-sided power loss on takeoff requires a quick and counterintuitive response. That requires consistent training, more than most pilots do.
In a small, recreational twin, the most common outcome for an engine misbehaving on take off is it rolls the airplane, taking down the whole cluster.