Yes Jimena dynasty is overpowered because Galicia, León, Castilla, Navarra and Aragón are allies and if one of them declares a war, the rest help him and the enemies, andalusians or County of Barcelona don't have enough power to fight against 5 kingdoms, because they don't have as many allies
EMF also still has some old code from PB that's been on my shit-list for at least a solid year that preemptively (as in, before total conquest of the duchies) expands the de jure territory of Portugal, Leon, Castille, and Aragon on SWMH as certain counties come under control of the Christians. I didn't write this code and have promised
@IoannesBarbarus ( whom thankfully keeps reminding me that it needs to be addressed-- every week, every day, every hour, every other minute

) that I'd replace it with something that makes a lot more sense.
The problem with the current code is that it basically makes a *bunch* of Muslim-held territory suddenly de jure Portugal / Leon / Castille / Aragon (without properly earning it first). This means that the Christians will inevitably use de jure county claims (or, worse in this case, de jure
duchy, as they don't seem to have much trouble hitting Medium CA on those kingdoms) to very rapidly *vassalize* those Muslims (whom they then proceed to Demand Religious Conversion and/or eventually revoke all their titles, but it's nasty in the interim) INSTEAD of being forced to use a Holy War CB to properly remove kebab and THEN potentially add to their de jure territory. This makes the Reconquista happen far too early, far too inaccurately in manner, and far too often successfully-- with a lot of overextension.
My fix will be sane de jure expansion (only expand the kingdoms de jure when the territory in question has already been outright conquered completely) combined with a Reconquista CB (a variant of Holy War) that doesn't require piety / requires less of it (tuned as necessary) and can be used by both the Christians and Muslims over the contested "Reconquista duchies" in Iberia. The special CB will only be necessary if the Christians can't seem to pull-off the Reconquista with this aforementioned, inaccurate kludge removed/fixed and standard Holy War, which is admittedly a tad piety-expensive for an AI that doesn't know good ways to earn piety like players do.