You are not taking demographics and social groups into account, for example in this source (you provided) have a look at the disparity. In Lebanon: (12.8 to 42 range in OP) Bekaa Valley (Sunni Bedouin), 47.2% (2007) All Lebanon - Household, 35.5% (2009) All Lebanon- Household (Shia), 28.0% (2013) In Jordan: (28.5 to 63.7 range in OP) All-Jordan, 39.7% (1992) Irbid, 50.6% (1993) Balqa, 40.3% (1993) Amman 25.5% (2005) In Saudi Arabia: (42.1 to 66.7 in OP) Riyadh, 42.3% (2007) Madinah, 39.2% (2007) Makkah, 32.4% (2007) Qassim, 29.6% (2007) Najran, 28.4% (2007) I mean for Saudi it seems to be overestimating if anything. And having looked at many of the sources, your earlier claim sounds like something of r/worldnews
The researchers are using outdated sources about other countries:
Excerpt from the study: Compared with other Middle Eastern countries, which follow the same religion and have similar traditions as Saudi Arabia, the consanguinity rates in our study population are higher than in Bahrain [23], Egypt [24–26] and Lebanon [27,28] but similar to that reported from Oman [29] and Yemen [30] and significantly lower than the rates in Jordan [31–33], Kuwait [34], Iraq [11] and UAE [35].
Lebanon - 1971 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R27
Lebanon - 1988 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R28
Jordan - 1966 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R31
Iraq - 1989 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R11
Kuwait - 1985 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R34
Egypt - 1971 and 1983 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R24 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196414/#R26
I didn't use that study to dispute the OP's Saudi Arabia consanguinity rate. I used that study to substantiate the claim that the researchers are using outdated information about other countries. Here's what I said:
In a 2014 study about KSA consanguinity rate in two generations, the researchers are citing outdated sources from 1966-1989 about other countries