UX person here. I can do the spectrum of work from BRD and research through to wireframes and prototypes, but I stop before visual design. You've enough detai

UX person here. I can do the spectrum of work from BRD and research through to wireframes and prototypes, but I stop before visual design. You've enough detail in here that it's probably not entirely you, but rather your organization. The org has probably hired artists not designers and doesn't know how to make them properly accountable. The simplest difference between an artist and a designer is who they work for. An artist works for themselves, a designer works for a business goal. An artist wants to be personally satisfied, a designer has metrics. I've never met an artist I would trust to also do research or usability design, however, so wanting to push them be UX people instead of artists is probably not going to work. However, you might be able to exert pressure by giving them design constraints. A visual designer isn't designing a UI for themselves, they're designing a UI for the users of their application, so their business goals are things like user satisfaction, user comprehension, and user efficiency. Do the users like the look and feel (measured with things like desirability tests)? Do the users understand what they are looking at and finding what they need on each screen (measured with comprehension tests)? Do the users get their activities done as fast or ergonomic as possible (measured with usability tests)? The last one you can directly influence on the engineering side. Chapter four of _The Humane Interface_ explains how to quantify usability. You can literally measure the usability of a UI and establish standards for performance, just like you establish standards for your code's performance. You can mathematically determine the minimum amount of input required to accomplish a task and measure the UI against that, with goals of improving the UI a certain amount over time. You could create test suites that measure a click path to see if a UI change improves or regresses it. Putting these design constraints in place and then making the designers responsible for hitting them are a good way to see whether they're really designers, or just artists.