Good enough for MBB/Tier2 in US?

Hi folks,

I did my undergrad studies in Germany, where I come from, and currently engineering grad student at MIT.

I pursue a career in management consulting. In Germany, I got invited by BCG and Bain for two smaller case workshops at my university and one year later by McK for a four-day-event which guaranteed an interview for every accepted applicant. Unfortunately I got rejected after the interview for a German office.

I wanted to give it a try in US offices, and started applications first with Tier2/3 firms (Roland Berger, Arthur D Little, Deloitte). Today I got a rejection by Arthur D Little, so that I am afraid my resume is just too weak for MBB US offices. I had applied for McK US in October but got rejected, but to be honest my Cover Letter and the way I wrote my resume were pretty weak, I also had just started at MIT and therefore no grades available.

My profile: MechE undergrad in Germany (Top 3.5% of class), one year research assistant, one semester teaching assistant, six months technical internship in well-known automotive company, volunteer in two organizations for 1.5 years in Germany (but no leadership position). Now grad student at MIT (4.8 GPA) and started last week volunteering in two organizations.

Is it probably the H1b issue that lead to the rejection? Shall I get my resume/cover letter checked by professionals? Or is my profile simply too weak for MBB in the US?