Is there an option to add another template in the same sheet?

You can create one sheet using multiple templates but you can only start with one template. You can then use other templates as a model to incorporate the additional column properties that you are after. You can then use this as your hybrid template. Or, you can contact your Smartsheet customer success manager and request access to a resource portal where you may find the hybrid template that you are looking for.

Templates are really just sheets, reports and dashboards that have functionality built-in already. You can use one templates set and then open another to copy or rebuild the functionality to effectively use both and then save it as a custom template that meets your needs.