If the brain is anything like computer hardware, the actual physical connectivity likely matters quite a bit. Consider what would happen if you randomly removed a single transistor on a CPU. Even though the transistors are very simple, virtually identical constructs the effect of taking any individual one out varies a great deal depending on what the transistor represents to the workings of the CPU. If it's involved in thermal regulation, it might result in spurious thermal shut-offs, performance throttling at incorrect times, bad fan control, or other problems. It could be involved in advancing the instruction pointer, which means that software on the affected core most likely wouldn't run correctly whatsoever. If it's part of a cache, you may get memory corruption problems that could be extremely difficult to diagnose. If it's involved in a rarely used calculation, you might never even notice that there's damage!