I wish that Shiradi Abilities did proc and scale from runearm attacks, but this is not the case.
To the OP, I have no gripes about Shiradi Champion for my Artificer. In my opinion, it is the best thing that ever happened for my Artificer. While an Archmage will utilize SC better than my Artificer, Shiradi Champion seems like it was made for the Artificer.
I assure you. You have not seen a fully geared/fated Shiradi Champion Artificer in action.
My Artificer's name is Deathaven on Khyber.