Their food is plain and good, their clothes fine but simple, their homes secure; They are happy in their ways. Though they live within sight of their neighbors, And crowing cocks and barking dogs are heard across the way, Yet they leave each other in peace while they grow old and die.

The neighbouring provinces are mountainous/highly variable terrain and historically difficult to traverse, so they would have grown up unlikely to have visited one another except in rare occasion. Nowadays that point is moot, where you'll find cuisine from all regions across most major Chinese cities, so they'd probably settle on one that both could tolerate