Saudi Arabia is ruled by Sharia law and is no. 12 in the world for median income per capita.
[Edited to add: Aha! I was looking at per-capita GDP not a median, Saudi Arabia does not estimate a median. So, could be anything depending on who you ask]
No Gini coefficent is available for Saudi Arabia, but do you feel like the millions of immigrant workers who can be executed on the say-so of their employers are sharing equally in that great wealth?
Also, to the extent that Saudi Arabia does treat women very poorly, it also treats men very poorly, and children, and almost everybody, even the rich aren't in great shape in Saudi Arabia although they enjoy a wide range of benefits (e.g. like the US, Saudi Arabia executes criminals, but, unlike the US you can agree to pay the victim's family blood money instead, which of course is easy if you're a billionaire)
I wouldn't be at all surprised, though, if it ranks much higher for mean income.
ie You phone people (do the immigrant "workers" on a Saudi building site have phones? Are they allowed to answer a call while working?) and you ask "How much does your household make each year?" and they make up whatever they want but you write that down, and you hope that the ludicrous high numbers and ludicrous low numbers don't make a big difference to the resulting outcome, which is probably wrong, but unlike official statistics (which Saudi Arabia of course doesn't keep) you at least got a number.
Since we’re on the subject of gender equality, I wonder what proportion of that income is controlled by women.