Help explaining questionable job change for B-school application

Hey all,

I'm wanting to apply to Top 15 MBA programs in the Fall and am honestly feeling a little insecure about a career move I made a year and a half ago. I'm 28, will have 6 years experience. My goal is to land an IB Associate gig, post-MBA. A little background:

I started out in Big 4 risk advisory and got promoted to Senior Consultant. The questionable move is leaving Big 4 for a large global bank to work in its regulatory report testing function (think audits over Federal reserve/capital reporting), with a weird change in title/job responsibilities.

I left Big 4 to get more technical experience in banking and see what the industry was all about. Also, the role I took had good opportunity/visibility associated with building out a fledgling program. After a year, I started a new role, reviewing federal reserve and capital reports, diving into the bank's financial statements. I understand banking financials quite well. The new role is less project management focused and more technical accounting focused. Been at the bank for 1.5 years total.

When I came to the bank, I took a job with an unofficial title within our group as "program management team lead". The bank itself gives you an official title though, where they start you out with a "consultant" title. But they only take people with 4+ years experience and start you out at that level (there are Big 4 Senior Managers who come over with a "consultant" title). How do I explain going from Senior Con to Con? Or do I lean on the group's unofficial title of "team lead"?

Also, the current work experience seems to have less leadership responsibilities compared to my former Big 4 role. The group's culture here is more collaborative and less vertical. I have had opportunities to lead side projects and whatnot, however.

I guess I need help with spinning this when it comes to writing my B-school essays, and then hopefully I get interviews and will be explaining this in person.

Thanks!