At least two factors may be at work here (for multiple control
points close together):

(1) Having multiple named points makes it easier to give
unambiguous instructions to train crews and singal
maintainers, particularly in the event of a switch or
signal problem. Example, crew receives radio permission
from the dispatcher to place the switch at X in hand
operation; or it receives permission from the dispatcher
to pass a stop signal at X.

(2) These may be considered multiple interlockings. Why
would you want to have multiple interlockings so close
together? The way it has been explained to me is that in
an interlocking, normally no new routes can be set up as
long as the interlocking is occupied. By having these
defined as multiple interlockings, you only need to clear
the immediate interlocking to clear its occupancy detection
and for the dispatcher to be able change switches in lining
a new route. For example, a work train or piece or track
equipment (some larger machines do trigger occupancy detection)
may be told to pull past control point Z so that the dispatcher
can line switches to a different track.

-- Ernest