These results clearly contradict the perldoc documentation:

That's not true. The docs don't say what happens if you use -l with -f func instead of a module.

Here's another anomaly

What do you think is anomalous? That it's looking up splice instead of $_? That's your error. You interpolated shell variable $_ into your shell command, and it apparently had the value splice.

And another one:

What do you think is anomalous? That output is correct too, and I have no idea what you think is wrong.