Would it be a better idea for me to sow zinnias in cell packs in a seed starting mix, let them germinate and grow on my deck (bringing them in at night when temps approach 45) and then transplant them into my mulched landscaping?

Or are they easy enough to germinate by direct sowing in the ground by moving some mulch out of the way, tilling the ground a bit to soften it up, sprinkling seeds in a random fashion, and then covering them up with the loosened soil and thin mulch layer.

I've never grown zinnias so this is new to me. If I take the first approach, I assume that the appearance of the zinnias will be less clustered than if I were to sow them directly in the ground. Does that sound about right?