Hi @zev1on,
Usually the position of the name fields are defined by the address format used on various places in WooCommerce.
I see you have a custom “Full name” field instead of the default separate fields “First name” and “Last name”. In this case, your custom field is considered as an extra field and will be displayed below the address fields which use the default address format.
You can use the hook fc_substep_text_shipping_address_field_keys_skip_list to prevent Fluid Checkout form adding that field at the bottom of the substep review text, and then add it at the top using the hook fc_substep_shipping_address_text_lines. There are similar hooks for the billing address as well.
Unfortunately, we don’t have documentation for how to use those hooks so you’ll need to check the code directly to figure out how to use them.
Please note that this type of customization is not covered by our support scope.
Best,
Diego.