I have two forms - one uses
<% form_for @user do |f| %>
<%= f.text_field :name %>
<%= f.email_field :email %>
<% form_tag send_request_path do |f| %>
<%= text_field_tag :name, '' %>
<%= email_field_tag :email, '' %>
The send_request_path sends an email request. It has no direct relationship with user.
In this case, you shouldn't be DRYing those two forms. It is so-called "accidental duplication". Two forms turned out having the same structure by chance.
Since the two things are not related, chances are good that implementations will diverge as time goes on. What are going to do then? Insert
if conditions in a shared partial?