Right now the testimonials in the testimonials page appear to show up in ascending order of date (oldest to newest).
This means that the first page of testimonials will always show the same ones, and since they are the oldest, arguably the lesser relevant ones.
My suggestion would be to reverse the order by which they appear, so the first page would show the newest testimonials and the other pages the older ones, keeping the content on the first page relevant and fresh (if the mentor is active).