The post is a 12monk/6fighter/2 whatever AND includes the PRR values for a 20 monk directly below it.
Try again.
The point that you are missing is that BECAUSE those options are there for monks, and increased inherent defenses would cause them to exceed the mitigation that full blown non-evasion tank builds get which causes a whole seperate sort of balance issues. Any increases to monk as a baseline would likely have to come with tradeoffs to their top end mitigation as it is extremely competetive with fighter tanks and exceeding that of paladin tanks.