the clutch piston/seal sufaces are actuated 20 times more than the brake seals, and with each actuation the seals in the slaves see a large range of motion, scrubbing against the piston. Unlike the brake seal/piston interface, where the piston barely moves .030 inch max under each actuation. This is what causes the fluid to degrade, and discolor more rapidly.
I suggest changing this fluid at least every other year, it will add to seal longevity.
DOT 3/4 is more than adequate, these seals were designed for that, wayyyyyy before DOT5 became popular.