I would keep two stamina trinkets and two agility DPS trinkets. Searing Words has a base stat of Crit, and it procs a massive amount of agility for 25 seconds, so it is actually a phenomenal Guardian trinket when you're looking for RPS to fuel SD and FR. On fights where the raw stamina / tank procs / extra tank cooldowns are needed, you can use Stamina tank trinkets. Otherwise, I highly recommend going with either two trinkets that incorporate both Critical Strike and Agility, or Searing Words (or a trinket like it) and one tank trinket.