In fact if you look through the historic top500 lists a lot of the space outside the top10 is occupied by industry clusters. Classically oil and gas has been one of the big consumers. In recent years there are more and more cloud clusters in there as well.
So this Tesla cluster isn't really anything unusual.
There are some companies that don't have centralized high-performance compute resources so each department goes out and builds or buys and their own performance compute resources and strings it along. Many universities do this too where physics has a compute cluster and economics and bio-sciences have another cluster and sometimes they are underpowered and if all the departments grouped together and pooled their resources they would have adept system administrators and developers and hardware to support their computing needs but it doesn't always happen with poor governance so they end up with stuff that appears to be built from someone's basement and when that person leaves, retires, graduates there's so much poor documentation none know what to make of anything.