The LAN controller used to make the Beowulf cluster would probably have more compute (and memory) than the 6502 itself.
The Intel cores in the linked article have a distinct L1 data and instruction caches inside them, and associated L2 caches, which makes a big difference in comparison to the 6502.
Intel did entertain a similar thought for a while, as far as I can understand: https://semiaccurate.com/2012/08/28/intel-details-knights-co...