I don't think how hard someone can climb should have anything to do with the selection of their first trad lead. You want an easy route with lots of bomber placements. Followed by several similar routes to build the trad placement skillset.
Exodus gets my vote.
I reckon Piccolo is a good early lead, provided someone can meet the newbie leader up the top and assist with the anchor. It's a tricky anchor to get right - thus why it features on the instructor course.