Neither al Nasir, nor his African followers were willing to stay endlessly on the Iberian peninsula. If he won a great victory, and was able to sate his soldiers lust for plunder, he would likely return to Africa with most of his followers, leaving his governors/generals in Spain.
Yes, this is my point. All these kingdoms that overlaped Al-Andalus and Africa have to be busy on two fronts : or they focused on Al-Andalus and other African families slowly conquered their African holds, or they focused on Africa and the governors tried to have an autonomous life, more ready to ally themselves with Christians than with the Muslim ruler.
One of the reasons why he was harsh on the Andalusians was because he really had less resources and he began to squeeze out too much from them, which in turn maddened them.
Again, and you say it, the Almohad had little choice, because no ressources enough to well rule the two provinces they have. So, it would be almost impossible for them to use few ressources for conquests.
While it is absolutely true that he was not secular or even pragmatic in religious matters, it might not matter too much if, after having won a great victory, looted the infidel (and ransomed all important Christian knights and noblemen whom he had captured, thus sating his African followers with rich rewards).
The problem is that the ransom would not be that importants. Only the royal ransoms were than important to allow such sating. And as "you" killed the kings (on a good purpose, it gives Almohads more odds)...
And even if it would be enough, gold call gold. You can't give someone a big ammount of gold if you're unable to regularly give him roughly the same regularly.
For Almohads it's possible only by trying to raid and invade the Christian states (and too to fulfill their purpose and legitimity on Andalucians' eyes : stop the Reconquista) and they don't have the ressources, the men or even the strategical possibility to do that at a great scale.
I could see them able to take back Lisbõa and to advence the border futher towards Toledo (without taking back the city) but it's almost all they can do.
If he leaves for Africa after his victory, leaving some of the army to chase the Christians (particularly Aragonese, who are badly weakened for the moment), what would his Spanish governor be like?
1) Many headfigures, fighting (not in battle yet) each others probably. At the minimum, one at Sevilla, the other at Valencia.
2) Not chasing the Christians. They didn't have enough men to focus on all the christian kings, and wouldn't tentate the Devil by chasing just one.
3)Probably using that the death of christian kings made sucession trouble happen in their respective kingdoms, to reinforce their positions.
4) Each depends on how much men stand in Al-Andalus. And the almohads are not like "Hey, if i let men of my own, to help ambitious ones to take more power?". At best, the soldiers stand loyals, against Andalucian milicias.
The important question here is - would Raymond of Toulouse be helped back on throne by al Nasir (or whoever was left in charge by the Almohad ruler, after he had returned to Africa)?
No, for four reasons.
1)Pyrenees. Hard to cross in the bad months, and passes controlled by everyone. The best way to reconcily Occitans and Frenchs nobles are a raiding army.
2)Aragonese. Even weakened, they have strong cities and castles. Every army willing to go trough, would waste months, lost many men, and not even sure to sucessfuly cross anything.
3)Castillans. I know a certain kingdom that would be more than happy to use the fact that someone would be playing with Aragon to take back some land and riches.
4)Muslims. Seriously, who would be dumb enough to go make a hike in hostile and difficult country, and let his wealth and lands to the first ambitious come?
In other words, would he/they do a successful Muret for Raymond of Toulouse in exchange for a secure border to the north, while they were busy consolidating his victories in Aragon.
The battle of Murèth wasn't lost because of the numbers. They were largely superior.
Not because of the terrain. Simon was almost surrounded.
No, the battle was lost because : the Occitan lords didn't care to follow Peìre II strategy, and that the Tolosan didn't even fight : Raimon just leave the battlefield.
The chances of this happening are not great, I agree, particularly because Raymond of Toulouse and Pedro the Catholic were related, while al Nasir has no reason to help.
And critically because : "
Hey, you declared a Crusade on me because i tolerated Cathars. But the fact that i'm allying with someone that just killed and crushed the Christian one year ago have nothing to do with that, and i hope that you and the Pope wouldn't be angry at, and that the King that stayed out of this mess wouldn't be enfuriated that an enemy army enter on his lands to kill french nobles!"
However, a pragmatic ruler might see the reasons for doing that. After all, there is no hope of coming to terms with a papal authority in the north. If the more secular minded Raymond were in power, it would mean less trouble for the Muslims in Aragon.
Raimon have NO reason to be more secular. The raimondine family was traditionally extremly catholic and this Raimon was maybe the first to be more tolerant about it, but nothing to do with the Trencavels.
Regarding the pope, there was an agreement with Simon's death and renoucment of his son OTL. He lost territories but remained a powerful and autonomous lord.
Actually, one of the great cultural fear of christian, would be the return of Muslims army.
As for consolidating the power in Aragon, it is not all that impossible. There were still large Muslim communities in Zaragosa and Valencia, both of which, barely a century ago, had been ruled by Muslims.
When they took Saragossa, the Christian expelled the Arabs out of the city to repopulate it with aragonese or occitan population.
In fact, the big arab population of Valencia came in part from this Saragossan exiled.
So, sorry, but a big no on this. Too much protected, too much homogenous, too few men to do that, not the possibility to waste months on a siege.
To resume, the only Muslim state that had a chance to perdure in Spain, was the Caliphate of Cordoba. Why? Because he focused on Al-Andalus, was "indigenous", quite tolerating (except the Aminid dictatorship) and before all that, never made the mistake to be too much involved in African matters, and had only "vassals" on the other side of Gibraltar.
It's the main reason for why it lasted around 300 years, and the sucessors state didn't.
At the best, Muslims can strengthen their borders, taking some land and fortresses. But not taking back what was lost since 150 years or even 50.