Martin (1992: 371-2):
The major advantage of the stratified approach is related to the problem of grammatical metaphor. Being less tied to lexicogrammar, the nuclear relations analysis is freed to recognise semantic continuities across a diversified range of realisations. Because the TRANSITIVITY structures are so varied, cohesive harmony analysis would give a very different account of chain interaction among the following messages than the nuclear relations analysis re-presented in 5.36. Australia II is an Actor in [5:36kk] but a Car[r]ier in [5:36ll]; similarly the Americans are a Medium in [5:36y] but an Agent in [5:36dd];
 Grammatical metaphor is raised here as a problem, but the supporting argument does not present examples of grammatical metaphor. Instead, it identifies (and misidentifies) a range of different participant rôles played by Australia II and the Americans — as if these constitute instances of grammatical metaphor.
 In SFL theory, the relation between semantics and lexicogrammar is clearly defined as realisation: the higher level of symbolic abstraction (semantics) is realised by the lower level of symbolic abstraction (lexicogrammar). In this model, semantics is thus not less tied to the lexicogrammar — it is simply that the relations between the stratal systems are neither thoroughly considered nor made explicit.