There is certainly much more to be said, but one problem at the core of your enquiry is the scarcity of sources for this period – specifically, the non-existence of absolutely contemporary accounts, and hence an ongoing debate over the reliability of the Chronicle of 754, which is the earliest account we do have of this period.

Historically, the tendency has been to downplay the reliability of the chronicle in favour of referencing later sources that do suggest the "invasion" of 711 resulted in a rapid and cataclysmic defeat of the Visigoths. But, as I commented in this earlier response...

To what extent can the Chronicle of 754 be trusted?

...some current historians have argued hard that the account given in the Chronicle of 754 needs to be listened to more carefully, and that does suggest the "fall" of the Visigothic kingdom was the product of a much longer process of pressure and attrition.