I would definetly also want mutliple arrays. That would give the ultimate felxibility to organize the storage of the server.
Every array with its own parity disk(s) would be an independet fault tolerance unit. Without speed and securtiy degration, if in another array a drive fails and the array needs to be reconstructed.
It would be possible to spread the risk over more disks when the data is split by mutliple arrays.
Statistically, the over all reliability gets lower and lower, the more drives you add to a single array with its max. 2 parity disks. With multiple arrays, this could be prohibited.