Abstract In addition to arguments, adverbs and non-arguments are considered potential candidates to occupy left peripheral positions. Following standard assumptions in syntactic locality, adverbs, non-arguments and arguments elicit distinct effects in terms of intervention locality if moved. Such an asymmetry is not expected if these elements are generated in the syntactic position they are spelt-out. In this study, we employ quantitative and computational methods to compare cartographic models differing in the merge nature and explore, as a diagnostic, the intervention effects (or the lack of intervention effects) predicted by these models. Specifically, we compare the observed counts in large-scale datasets to imputed expected frequencies on the basis of the models under investigation. To reach this goal, we extract grammatical clauses from morpho-syntactically annotated treebanks of Chinese, English, French, German, Hebrew, Italian and Swedish. Our findings reveal cross-linguistic levels of complexity and typological variability, consistent with the predictions of featural Relativized Minimality.