Avira > one of the most esteemed experts in chasidus
I think one problem with Chabad is insularity of their education: many do not appreciate Torah coming from other sources. This may be side effect of preparing bochrim for action early. Someone who is going to build a Chabad House in Iowa may not have time or focus to learn deeper. But this has to come with appreciation what the movement achieved. If you sit and learn all meforshim, while disparaging all other movements, you may not be on a greater maalah. There are a lot of sources saying that mesiras nefesh and involvement in community matters is worthy even if that decreases your limud (starting with Mordechai’s downgrade).
I found bringing up Vilna Gaon (as little as I know or understand him) works perfectly in increasing their awareness of the world :).