What worries me is that, while strict is perfectly happy with it, the code below has a run-time error that may not be triggered for hours/days/weeks/months/...

Okay... So does the equivalent static dispatch table.

use strict;
use warnings;
;;
sub hiya { print 'hi from ', (caller(1))[3]; }
;;
sub _x_foo { hiya; };
sub _x_bar { hiya; };
;;
my %disp = (
  foo => \&_x_foo,
  bar => \&_x_bar,
  zot => \&_x_zot,
);
dd \%disp;
;;
$disp{foo}->();
$disp{zot}->();
$disp{bar}->();
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You have to write code for each piece in order for the whole thing to work reliably, but you may not discover that it doesn't until a very inopportune moment. If everything could be thoroughly tested prior to deployment, the queasy feeling in my stomach might be eased a bit, but even so...

This is true for all Perl code though. There's a gajillion ways to write a script that "compiles" with strictures enabled but fails at runtime. This is why we write tests (unit, functional, etc).