You're reading me wrong on this one. I do not presume that either side will simply give up regardless of who is victorious at Los Navas. I also do not presume to glamorize Christian Iberia. Often, Christians were more prosperous and certainly Jews were safer under North African Muslim rule than later Christian rule. Christian injustices towards Iberian Muslims and Jews amply predate the 16th century Inquisition. It is noteworthy to know that the Islamic forces' desire for land and power consolidation was probably just as strong as the crusade called for by Pope Innocent.
I will say, however, that the Almohads had just as much internal dissent as Castile, Navarre, and Aragon. Towards the middle of the reconquista period, and certainly in the Granadan period, there was a feudal political system developing in Islamic southern Iberia. Rival North African tribal groups swept in and out of the remaining Islamic holdings and established fiefdoms. Would the Christian kingdoms have been able to exploit the developing Islamic political turmoil if they lost at Los Navas? Perhaps not. Still, 13th to late 15th c. North African rule of southern Iberia was marked by succession struggles and frequent disputes over land. In some respects, in OTL the Christians were lucky to capitalize on Islamic political turmoil. Christians might not have been as fortunate if the winds of Islamic Iberian political change were not at their backs.