Core personality needs are not the same thing as career. For core personality needs, always look at the sun first: its placement and its aspects.
That said, if someone with a splash chart asks what kind of career they should follow, I would advise them (and I have, in this situation) that they need to keep their fingers in multiple pies. Even if they have one job, they also need room in their life for other serious interests. And with that kind of chart, no single career will completely fulfill their needs. They might go through multiple careers in a lifetime, and no matter what they're doing for a job, they'll also need their other interests.
So for work, the important thing is that whatever they do pays the bills, doesn't drive them crazy, and does leave room in their life for their other interests. Their job may meet some of their needs, regarding career and day-to-day life, but it won't fulfill all of them, so they need to use their other interests to meet the needs that their job doesn't.
Now, I would expect that whatever work they do, it will fit their sixth and tenth house parameters. But they might go through multiple kinds of jobs that all fit those parameters, in different ways.