I do think that several factors go into a catcher's reputation of
having a strong arm. One of which is the pitching staff-- are they good
at holding on base runners, which would either make it more easier or
more difficult for them to throw base runners. I also think that once a
catcher gets a reputation of having a strong arm, teams are less likely
to run on them, i.e. test out his arm. It's the same thing with whether
or not, teams want to try to take an extra base on an outfielder
(a.k.a. Ichiro). As far as, catchers with a reputation for having a
strong arm, one of the best is Ivan Rodriguez. One of the worst, as far
as reputation was Mike Piazza, although he could certainly hit.