Littleton might not be any better against the run this year but with Kiser as the other ILB Littleton won't be asked to play the run as much. Littleton is taking the role Baron played last year and will cover backs/TEs a lot more this season while Kiser assumes Littleton's old job and will focus more on run support.
Littleton's skill sets fit his current assignment better and without ever seeing Kiser play a down at ILB in the NFL his college resume says he'll be better against the run than Littleton.
Kiser will come off the field in nickle/dime sets, allowing the Rams to leverage his skills on obvious run downs and minimize his shortcomings on obvious passing downs.
AlbaNY_Ram