Recommendations for ASM Storage Preparation (on FLASH DISKS)

Hello - There are: 2 Flash Storage, wiith 2 controllers each, 8 interfaces, sector_size 4K - Going to create ASM with: 2 Failower group (1st group - first flash storage, 2nd group - second flash storage) in each disk group (except thouse group where is 3 failover group required). - Found Doc: Release 12.2 Administrator's Guide -> Recommendations for Storage Preparation > but there is no recomendation for FLASH DISKS - QUESTIONS: How many flash disks in each disk group should we have? What is the best way to group 8 interfaces? (4 flash disks in each group for one I/O path OR 4 flash disks on failower group per I/O path are required? Or it is not related to flash disks?).