JKM -- the weird number is 5.381.
This slope and CR say bogey golfer will shoot around 108 at TP from the tips. We just had a mini-test of that. One 6 handicapper shot 98...another 6 shot 100...and an 8 shot 114. What would a 20 handicapper, who drives the ball 200 yards, have shot there? 120? 130? Don't know, but a whole lot more than 108, I bet.
I know they use adjustments when doing slope. Even so, slope at TP should be 155. Better, drop the 155 cap. Better still, drop slope altogether and use Bogey Rating instead.