Can you provide us on what basis they are ranked or the site used any algorithm script? Whatever it is, I have some concerns about the method you used to determine the rankings as apparently most would not agree to them. For example, I have two favorites here: Fairspin and Betplay Meanwhile Rollbit was not good for me. The withdrawal took too long.
Based on his original post, his ranking and reviews are based on his experience while playing on the website. just like you probably had a bad experience with Rollbit, his bad experience is with Fairspin. as for Betplay, the ranking gap between Rollbit and Betplay is not far.
He can always check the first page and he can also check the main review site to see if the reviews looks so good to him but we all won't have the same experience in playing the site. It could be that by the time he made a review the site ran onto some problems causes for his withdrawals to delay or something else.
Not sure what an algorithm script can do to a site like this, since this was only just a plain site made to post reviews from gambling sites but if ever you disagree, you can always post your own comment on their website, since they have a comment box under the review or you can just completely ignore what he said. What matter is still our own experience.
I also don't think gamblingbro has algo script for the ranking or rating. As you can see, he has one of the most comprehensive reviews you can find about gambling casinos. The rating is subjective in my opinion. As he is publishing about his experience, it is true, that your experience may deviate from his experience. But you can always share your experience by posting in the comment section. His reviews are also not the absolute reference. But he is doing great job of detailing his experience per feature of the site. Also, some may change as the site also updates their features.