Hi,
It's not possible to combine both search processing modes. It's either both words, or any words. To be able to search with both modes to provide the products like you want, it would basically require running twice the products listing's main MySQL query and combine the results. This would require complex modifications to achieve, and slow the page processing, and cause issues with the pagination system.
I don't see an easy way to do that.
I think the simplest would be to directly modify the file components/com_hikashop/views/product/view.html.php in order to dynamically change the products listing loading query in the listing function to use a UNION of twice the same query, changing only the filters on the columns of the filter when the "every words" mode is selected.