I
agree with you. These methods sometimes work, although there is no guarantee that
they will always work.
On the other hand, and this is the good news, we can't know how
often this approach will work until we explore it at length. It may
work in a large number of cases.
The relativist is committed to the view that there may be cases in
which two conflicting moral judgments are both true. In these cases
there is no resolution even after all the consequences are agreed to
and considered and all the logical inconsistencies are eliminated. But
we don't know how often this actually happens. It could be that it is
rare. The frequency of such cases is an empirical question. The theory
of ethical relativism tells us nothing about the frequency.