It is still not known whether a shortest common superstring (SCS) of n input strings can be found faster than in ^O*(2ⁿ) time (^O*(̇) suppresses polynomial factors of the input length). In this short note, we show that for any constant r, SCS for strings of length at most r can be solved in time ^O*(2 ^(1-c(r))n) where c(r)=(^1+2r2)-1. For this, we introduce so-called hierarchical graphs that allow us to reduce SCS on strings of length at most r to the directed rural postman problem on a graph with at most k=(1-c(r))n weakly connected components. One can then use a recent ^O*(2^k) time algorithm by Gutin, Wahlström, and Yeo.