Frankenreich, et al, were so decrepit in those times that it really wasn't worthwhile for the Moslems to try to rehabilitate the place.
Consequently they escorted Moslem converts from the area back to Spain where it was sunny, warm and civilized.
"...leaky thatch roofs..."
Quality thatch roofs do not leak. Today one is likely to find better thatch work in Natal/Zululand than in Central America but even in Europe there are some who keep the almost-lost art alive.
So you think the Mohammedans just turned around at Tours of their own accord...a unique theory...completely faggy and perverted but different.