I think it depends on how many rifles a person intends to have. More rifles means more diversity.
For example, if I were to only have one rifle to do everything: 6.5CM AR-10
If two: 223 AR-15, 6.5CM Bolt
Three: 22lr, 223 AR, 6.5CM
Four: 22lr, 6CM Bolt, 308 AR-10, 300 WM
Five: 22lr, 300blk...