Defective construction and verbal taʿqīd both involve sentence structure, but their diagnostic criteria differ. Defective construction breaks the established grammatical pattern; verbal complexity makes the intended relationships hard to discover because of the distribution of words.
Defective construction: «جزى بنوه أبا الغيلان» — the pronoun precedes its antecedent in wording and rank.
Verbal complexity: «جفخت ... بهم شيم ... دلائل» — displaced elements obscure the intended connections.
Both defects could coexist, but difficulty of interpretation alone does not prove a violation of grammar.