general cluster design discussion

after looking closely into LVS and how IWorx-CP works using clustering feature i was wondering why not do the following to descrease the point of failure:
1- since home dirs are hosted via NFS why not run multiple mysql servers on the same httpd servers (nodes) ?
2- and have the /var/lib/mysql an NFS mount point on the Nodes from the NAS hosting the shared storage
3- where all servers will access one external disk that hosts their home dir/files and database files ?

Using the MySQL native clustering or native replication would be better Bashar. MySQL can have issues with locking on DBs shared over NFS and from what I’ve read it’s not recommended.