An assembly type item in QuickBooks is correct to use if you have a finished good that is made of raw materials that is stocked as a finished good and is not easy to disassemble. A good example would be a manufacturer who sells bike parts and makes bikes from those parts that they keep in stock anticipating a sale. In order to convert raw materials into a finished good you must use ‘Build Transaction’ in QuickBooks. This is what reduces your raw materials and increases your finished good.
A group type item in QuickBooks is correct to use for items that are commonly sold together, but are still independent items and stay that way until an order is picked. A good example is a gift basket or a 10-pack. These things can easily be disassembled and it doesn’t make sense to make them in advance of a sale.
For most eCommerce retailers that sell bundled products group items are the correct item to use in QuickBooks. If you are truly manufacturing finished goods; then you will be using assembly type items.
Remember that you want QuickBooks to mimic what you are doing in the real world. If you are stocking completed finished goods on your shelf that are made of individual item; that is an assembly. If you are pulling the items off of the shelf when an order comes in; that is a group.