وَإِنْ لَمْ يَقْصِدْ تَشْرِيكَ الثَّانِيَةِ بِالْأُولَى
If participation of the second clause with the first is not intended.
Two clauses may lack an external case position yet still be linked for a common communicative purpose. If attaching the second to the first implies a shared judgment not intended by the speaker, separation becomes preferable or necessary.
“Sharing a judgment” does not simply mean that both clauses are grammatically declarative. It means that the speaker intends the second to participate meaningfully in the same connective act of discourse.