Attacking a person as opposed to an argument is Ad Hominem, claiming experience as a qualifier for correctness is an Argument from Authority. It can lead credence, but not make it veridical.
I am using the same data as you? Go look at the report CecMiller provided. It shows an example of a RDM having less uptime than the NIN. If you do look at more examples you will see that it is the case that it fluctuates based on personal skill, time for the fight, etc. Generally around that 1-2%.
In fact heres the best BLM and SAM reports on the site for Susano.
https://www.fflogs.com/reports/k94fg...pe=damage-done
https://www.fflogs.com/reports/V9kja...pe=damage-done