But i like that! I like Big orc brutes like Ugluk, Lurtz, Gothmog or Azog...
But i also liked Sneaky, yet tough orcs such as Grishnakh, Gorbag, Snaga far more. An intelligent sceming orc, who is not necessarily physically imposing but has an interesting, dangerous personality i would like.Therefore i understand why Ken Leung or Temuera Morrison... they have a great charisma and should be able to give a leaving impression even after few short scenes just as you said.
I still like Bill Burr too though