Unlike what this role is presented as to internal hires, it involves minimal writing or argumentation. Internals with years of experience are hired into an "associate" role while externals a year out of college are hired a level up. These "associates" publish reports, for upwards of a year, under the names of people who typically had nothing to do with their creation. Copy-and-paste busywork from the broader group gets dumped on these "associates", so someone 1-5 years out of college spends more time pasting bits from one spreadsheet to the next instead of learning about the financial industry or establishing oneself as an analyst. The opportunity to write research pieces on the industry is routinely played up in the job description and hiring process, but this is BS: such opportunities barely exist, and when they do, it's yet again more copy-and-pasting old pieces and replacing some numbers.
The group itself is split between people with 5 or fewer years of experience on one side, and people whose main priority isn't professional development on the other. Salary is lackluster. Internal work on reports is very high level and – surprise – is mostly copy and paste. For the prestige that Morningstar seems to think this group carries, the behind-the-scenes is unimpressive.
To internals: absolutely do not apply; you'll be nothing but cheap labor with lots of potential career progression time utterly wasted. And to externals: why would you want to work at this kind of company?