If the hiring is coordinated by the HR department, they may hire you under some sort of graduate program (Be it a MA program or just another graduate program). They may impose certain requirements such as 2nd upper honors because they need some sort of filter mechanism to sieve out candidate (not possible to interview so many). If so, then academic qualifications become important.

However, the department may also source and hire direct candidates. Most banks require department managers to source internally first. This means that the HOD will look for familiar people within the bank, who are doing other functions and who have expressed interest to join corp banking. This was the process when our team hired an operations lady to join as a RM, a few years ago.

When we need incremental support staff within the team, we hire RAs from pool of ex-interns or simply recommendations.

As can see, networking and inter-personal skills are the best means to get hired into any department (not just corporate banking).

We hired a girl with a Pass degree from a local uni. She couldnt even speak proper English but she had a very good attitude. She was a friend of an intern who hanged out with the team during our lunch time etc. Very fun and likeable person. Boss like her attitude and now she is a full-fledged RM back at my former team.