Help understanding validation

Can someone please help me with my understanding of validation. I have tried to find the answer for this question but have not been able to as of yet and I am hoping all of you might have my answer.

Lets say i have two models with two tables.

1. Product::model

2. Price::model

3. products::table

4. prices::table

I have fields from both that are used in my crud for products in my eCommerce build. My forms run through my Product involving the following:

PRODUCT FIELDS: name manufacturer details description

PRICE FIELDS: price model sku upc quantity alt_details

My question is do i put the validation to use in my ProductController like this:

 $this->validate($request, [
            'name' => 'required',
            'manufacturer' => 'required',
            'price' => 'required',
            'details' => 'required',
            'quantity' => 'required'
        ]);

or do i need to split them up and put them in a combined request like CreateProductRequest or put them in their corresponding models?

Does the flow of data make then look like one combined model / controller determined by the relationships or are they separate and need to be addressed that way.

Any help understanding this would be helpful and thank you in advance.