Is there any way from a surface controller to render partial views related to published child document types?

What I want to do is to keep my views as code-minimized as possible, leaving most of the code in my surface controllers. When it comes to generating various partial views relevant to the published child document types, it seems that the only possible way to do so is by using a foreach loop inside a partial view. But is there a way that I can move this loop to a surface controller, so that the partial view remains simplified?

This is what I've considered doing:

• In my View, I activate a Html.RenderPartial
• In my Partial View, I call the Action in my Surface Controller, where I want the loop to iterate
• In my Surface Controller Action, I want to generate a foreach loop for every published child document type
• In my loop, I want to use a switch based on DocumentTypeAlias of the child element
• In my switch cases, I want to activate an ActionResult method for the specific case, wherein I return a PartialView for that child element.

I've tried this way of solving the task, but the loop cannot show the partial views, that it's supposed to render by each published child element.

Does the activated string Method (called from the partial view) have to be of ActionResult type for the nested ActionResult methods to work properly?

And can an ActionResult method return multiple child ActionResult values?

Or is it not possible to generate this kind of loop with multiple partial views inside one Controller?

Here is an example of the code from the SurfaceController:

public string GetFrontPageElements(PageViewModel model)
    {
        StringBuilder _sb = new StringBuilder();
        UmbracoHelper umbHelper = new UmbracoHelper(UmbracoContext.Current);
        bool existsButUnpublished = false;

        Node frontpageNode = GetNodeByAlias(model.ParentAlias, out existsButUnpublished);
        if (frontpageNode != null)
        {
            _sb.AppendLine("<link href='~/css/customstyle.css' rel='stylesheet' />");
            IPublishedContent frontpageContent = Umbraco.TypedContent(frontpageNode.Id);
            foreach (var partialElement in frontpageContent.Children)
            {
                switch (partialElement.DocumentTypeAlias)
                {
                    case (firstPartialView):
                        CreateFirstPartialView(frontpageContent);
                        break;

                    case (secondPartialView):
                        CreateSecondPartialView(frontpageContent);
                        break;

                    default:
                        break;
                }
            }
        }

        return _sb.ToString();
    }

    private ActionResult CreateFirstPartialView(IPublishedContent parentContent)
    {
        return PartialView("FirstPartial", parentContent);
    }

    private ActionResult CreateSecondPartialView(IPublishedContent parentContent)
    {
        return PartialView("SecondPartial", parentContent);
    }
    // more similar methods to come for the rest of the switch cases