For the best data security, would it be better to run a RAID1 array with 2 different brand hard drives (such as 1 WD and 1 Seagate), or to use 2 identical hard drives?

Normally for a RAID array you want to use the exact same hard drives, but I was thinking for a RAID1, it would be better to use 2 different drives to reduce the chance of both drives failing at the same time.

Any thoughts on the matter?