Why Japan adopted the B6N Jill

Why did the Imperial Japanese Navy adopt the B6N Jill when some improvements over the B5N Kate were modest?

Its much greater range offered an exceptional ability to find and strike an enemy from beyond the reach of contemporary carrier torpedo bombers.

The aircraft's roughly 487-mile range improvement over the B5N Kate was large enough to change where a Japanese carrier force could launch and still recover its torpedo bombers. It could let an air group strike before opposing scouts had even located the Japanese carriers. Range therefore affected the sequence of detection, decision, and attack rather than merely adding a favorable number to the specification sheet. The B6N's operational reach could justify adoption even when its other improvements looked incremental.