3 firewalls in HA

[bbache99]

Hi guys, What are the advantages of having three boxes operating in HA? Would it be more efficient to upgrade from 2 x HA firewalls running A-P to a bigger box in HA or to add an additional box to the existing cluster? Essentially, 1000 users behind 2 x 200B (falling over) - would adding an additional 200B to the cluster give equal results to swapping 2 x 200B for 2 x 300C? Thanks