In your first example, the Accusativus Graecus is [face=SPIonic]ka/rh[/face] "heads" : it is about the Achaeans, long-haired "as far as their heads were concerned" (i. e. we say nothing about their legs...)
You are right in the second example : Ulysses is sorrowful "as far as his heart is concerned" (maybe not his reason).
Other example :
[face=SPIonic]Sku/qhj to\ ge/noj[/face] "Scythian by his race" (maybe not by his habits)
By the way, the name Accusativus Graecus was given by Latin-speaking people, because Latin expresses it more often by means of the ablative.