The profiles are clearly meant to represent the same person, so you should agree to the merge.
Have you contacted the manager of Robert Venables-2438 ? That profile has a pre-1500 birth date so I do not think you will the able to complete the merge, though you can approve it. But the profile manager is pre-1500-certified, with quite a lot of research experience, and you will be able to discuss with her what information should go into the merged profile.
The information about Robert Venables on the Wordpress site (at this page ) is not clearly sourced and will need to be verified. A site like this on the web is, on its own, not a reliable site for a pre-1700 profile. I note that it gives no birthdate.