From somebody with inside knowledge.

“I don't think there's much room left at Malvern, so I don't think Malvern can operate all of route 58. Currently Malvern operates about 75% of route 6 (Brunswick has only seven runs on that route).

[And just daydreaming....]

There's still room at Glenhuntly so I suggest that route 5 goes to Glenhuntly (85% shared with route 64) to allow more trams at Malvern to run all of route 58. Hey, let's start a rumour about 5 going to Glenhuntly! Perhaps not. [Because there is not an atom of truth in it]

Regards,