WordPress cluster using NFS

We’re considering creating a WordPress cluster consisting of 2 web servers connected to shared storage (probably via NFS) + 2 database servers. There will be a load balancer in front of the web servers. I was wondering how best to divide up the WordPress files/directories between the web servers and the storage. Should only the wp-content directory be moved to the shared storage and all the other files remain on the web servers? Or should all WordPress files go to storage (I’m referring to all WordPress files starting at the root level, such as wp-config.php, wp-content, etc.)?