Oh dude, your faith is touching but I really don't think David Boreanaz would've done better with German in a German accent than English in an Irish accent. I know this because of my learnings, i. e. his Korean is actually much worse than his Irish accent, insofar as I am able to tell.

(Yes, they actually had David Boreanaz speak Korean in an episode of AtS.)

MANPIRIC WASHSTACHE!