I would say that if Davis wanted to remain in his position as head of the rebelling provinces, he absolutely had to demonstrate resistance to the "invading Yanks." A wiser--or less desperate--man would have practiced forbearance. Who knows what would have happened? Would reconciliation have been likely? Perhaps, but without the resistance to unilateral secession that the Union displayed, we certainly would have split long ago, and would have been perpetually doomed to the intracontinental squabbles that has plagued Europe for all of recorded history.
Of course, this is all speculation based on the little I know of Confederate politics of the time, but living apart from those times and given the gift of hindsight, it seems reasonable.
The answer could be simpler than that. Davis knew that if the Confederacy was to survive, much less thrive, it needed the larger border slave states. North Carolina and Virginia were vital for their survival. Without them the Confederacy would always be an economic colony of someone. With them the south might even win the war.