So much depends on your personal geometry. Look at the guys in the two photos you posted. The first one seems to have longer legs relative to the size of his torso, compared with the second guy who is more evenly proportioned. Note the difference in posture.
Your stance doesn't have to be narrowed so much, you just want your arms to fit outside your legs. If you expect you're on the longer legged side, I think take a somewhat wider stance.
The kinds of stretches that help me with deads target mainly hip flexors and hamstrings.
In the attached photo, the panel on the left is with hips positioned too low, in the center hips are a bit high, and on the right things are set to evenly distribute the strain.