One of the most important ways to protect a website is to have a secure password. However, it is no use having a strong password if there are other admins on the website with weak ones. The users to your website need to be managed. The more people with admin access to your site, the more chances that something can go wrong. Admin access should only be given to those that really do need it. You also need to make sure that those other Admins follow good website security processes.
It is important the staff that leave or transition into other roles, that they are updated or removed. The worst case scenario of this is that a former staff member, website designer or outsourcer with admin access goes rogue.
How can we help? We regularly check who has access to what on your WordPress website. We monitor it for changes.