The models also differ in their treatment of grammatical metaphor
In c) as ‘stratal tension’ between discourse semantic and grammatical systems (both contributing to meaning of metaphors), so conjunction is realised congruently as clause complexity, and incongruently as transitivity or circumstantiation
In b) as ‘re-mapping’ between semantic meanings and their grammatical realisations, prompting the treatment of an ideational metaphor as clause rank complexing (‘not simply because the vision…')
In a) Tom’s comment suggests that the transferred meaning is treated as function, and the grammatical realisation as structure.
Rose presents the difference between how Martin's derived model (c) and Halliday's original model (b) treat grammatical metaphor as a distinction between a 'stratal tension' and a 'remapping' between content strata, but since both involve the distinction between congruent and incongruent grammatical realisations of semantic features, 'stratal tension' is largely Martin's rebranding of Halliday's idea in less precise terms. In this regard, there is the question of what a model of semantics needs to provide in order to be able to distinguish congruent from incongruent realisations in the grammar and whether the 'discourse semantics' model satisfies those requirements.
However, Rose implies, by inclusion vs omission, that it is only in Martin's derived model (c) that both strata contribute to the meaning of metaphors. Of course, given that grammatical metaphor, like all semogenesis, involves a realisation relation between strata, it is nonsensical to say that one stratum does not "contribute".
More importantly, as Halliday & Matthiessen (1999: 283) point out, the metaphorical form is junctional: it also embodies semantic features deriving from its own incongruent lexicogrammatical properties. That is, grammatical metaphor is a means of simultaneously construing the meanings of both the congruent and incongruent grammatical realisations.
These two meanings are themselves in an elaborating token-value relation within the semantic stratum, with the metaphorical Token realising the congruent Value (Halliday & Matthiessen 1999: 288).