«خَفِيٌّ ضَيِّقٌ وَخَافِي ضَيِّقٌ»
Hidden and narrow; and one concealed is narrow.
A pair of associated descriptors can illustrate a relation, but it does not automatically prove the rhetorical validity of joining two full clauses. Coordination of attributes, coordination of predicates and coordination of independent statements occur at different grammatical levels.
The relevant objection must therefore be assessed at the level to which the proposed jāmiʿ actually applies.