It's not so much as stress as it is a bigger work load for them, which then causes stress if they have to do it. This is the problem with it:
Concepts get proposed > Staff debate over it whether it is a good idea or not > Concept gets approved > Concept gets postponed for a time when it can be worked on
This happens lots of times. Artists still have a ton of things to do so they need to be working all the time on their own project. Even if the concept artist was to draw something pertaining to their project, it would still result in the artist having to redo the sketch and they could have done it themselves.
Sorry if I seam mean about this, I'm trying to explain it as easily as possible. I do like the idea, but I just don't think it will work. I think Res needs digital artists first before considering an idea of concept artist.
And I'll add that this is just my opinion, it probably isn't a fact. If Patrick or xee (she's in charge of the artist department) think it's a brilliant idea then I'll be glad!