  In the Shortest Common Superstring problem (SCS), one needs to find the
shortest superstring for a set of strings. While SCS is NP-hard and
MAX-SNP-hard, the Greedy Algorithm "choose two strings with the largest
overlap; merge them; repeat" achieves a constant factor approximation that is
known to be at most 3.5 and conjectured to be equal to 2. The Greedy Algorithm
is not deterministic, so its instantiations with different tie-breaking rules
may have different approximation factors. In this paper, we show that it is not
the case: all factors are equal. To prove this, we show how to transform a set
of strings so that all overlaps are different whereas their ratios stay roughly
the same.
  We also reveal connections between the original version of SCS and the
following one: find a~superstring minimizing the number of occurrences of a
given symbol. It turns out that the latter problem is equivalent to the
original one.
