Should not be affected by athletics/strength/etc...
I would always hate it when I had an escort quest...I would walk and they would get too far ahead....I would run and it would look ridiculous.
Is it just me that this bothers?
My characters tended to walk faster than the charges. Never bothered me.
Also, in real life, walking speed depends on your habituated speed (and perhaps athletics) in real l life. Ask someone who's in the Army; it was my observation that the soldiers typically outpaced their significant others due to the specific stride length when marching, or making a timed ruck march.
As for it looking rediculous, nope, never downed on me to view it in that way. I just thought it was a pain in the rear...which it would be like in in real life.
So, long story short, it doesn't bother me.