«زَيْدٌ شَاعِرٌ وَعَمْرٌو طَوِيلٌ»
Zayd is a poet, and ʿAmr is tall.
One predicate concerns literary ability; the other concerns height. Unlike poetry/writing or tall/short, the predicates do not obviously share a single field of comparison. In an ordinary context their connection may seem arbitrary.
A special context could still make the combination relevant. Therefore the rule is not that the words are intrinsically forbidden together, but that a suitable jāmiʿ is absent unless the situation supplies one. Rhetorical appropriateness always depends on the intended relation.