Suppose you do a simple addition on your 4096bit "CPU", you have to propagate the carry from the first 64bits to the next 64. How do you do that within your clock cycle over the internet? You'd have to pipeline them so that each subsequent 64bit add waits for the previous carry, but then wouldn't it be orders of magnitude faster to just do it on the same CPU rather than taking the time and resources to do a single 64bit add followed by a high latency network transfer? At any rate what does clock synchronization buy you here exactly, data transfer are still high-latency and high-jitter, at best you're isochronous but definitely not synchronous.

Either I completely misunderstand what you're proposing or it doesn't make sense at all.