Fourth, what possible benefit would the Japanese accrue from a disposal of Sydney?
Basically, it seems to me that this is one of the more unbelievable of theories among many. Like many theories of this nature it attempts to address an event which is unfathomable but true. It attempts to answer the unanswerable. What happened is that a battle tested RAN cruiser happened across a German raider and Kapitan zur see (I believe) Detmers got the drop on his adversary.