Hi Ron,
The 5.6 amp figure I mentioned was for all 56 LEDs in a single row (spanning 7 driver boards) lighted at the same time (unlikely) at 100-ma or approximately 12.5-ma "average" current with the 1/8th duty cycle. The Vishay Si2312BDS is rated at 5.0 amps (5 seconds) and up to 15.0 amps in "pulsed" mode with the usual junction temperature and heat sink disclaimers. Now even though most of these LEDs have a max' 100-ma "peak" current spec', I suspect they would work just fine at higher "peak" current levels at a 12.5% duty cycle, yes, no? Each N-FET row driver is on 1/8th of the time. The MIC5891 column drivers have 500-ma outputs which only drive one LED at a time so they should do fine sourcing 100-ma or even 150-ma to each LED, yes, no?
Mike