SCH can be completely clueless in lower level dungeons and instances. You can do /follow on the tank and go AFK and have no issues, but that would be wasting your learning opportunities. The WHM at low level is seriously gimped and you will find it hard to solo anything at the lower levels. It is after you get both to level 50 that you need to start worry about the mp management, regen agro, vs pet control issues.