This seems pretty simple to me.
We don't know if Fisher would be better at LT because he didn't play that position last year. He struggled at RT. Was that because he was playing hurt? because he was playing out of position? or just because he was a rookie learning a position he had never played before? Regardless, he show marked improvement toward the end of the season and will only continue to get better.
We know Stephenson can play either LT of RT, so here is the obvious solution: Let Fisher compete for the LT job. That is the position he was drafted for and the position he excelled at in high school and college. If he plays LT better than he plays RT, put him at LT. If he doesn't, leave him at RT. Pop Stephenson into whichever position is left.
***Official Chiefs Crowd Game Thread Starter***
MatthewsChiefs is an okay guy ... I guess.