Have about 20 array online, with different hardware brands. I use Seagate drives almost exclusively, mostly LC in 18, 36,74,147 Gig, 10K and 15K rpm ( most arrays are under 5 years old). I never "mix and match" drives; and order drives in one batch so I obtain the drives in the same lot, and with the same firmware.
Rarely do I get a failed drive, and have not lost an array in over 6 years. I should leave offerings to the Seagate AMI, and LSIlogic Gods.
Since you have two identical server, sounds strange. Firmware and drivers, especially firmware can create false drive failures. Had this situation with an older model AMI adapter which behaved properly only after a firmware update. Check with the manufacturer before updating, firmware flashes have been known to destroy data. More hardware details would be helpful.