The errors are added to the model in the order they are run in
validations and have no relationship to the order they are in your
form. So, its not an easy fix.
In my opionion, its a better user experience if the messages are next
to the actual error field. That way users don’t have to shift their
attention to the top and then back to each field they need to
correct. They can just move their focus to what needs to get fixed
and see all the helpful information you are providing to them. So, in
case you do decide to do it that way, here is what an actual form
piece looks like in the manual setup that I might use.
Now, to get to what you’re looking for (not having to add that to each
form field). I did find this post, where they override how rails
makes the highlighted box around the form field to highlight the
error. They put the message there as I was doing, but it looks like
this way will do that automatically for you.