Since 1920x1080 and higher is standard today, it makes no sense to additionally use a graphic in a smaller resolution if you use a Full HD version anyway. That would only make your game unnecessarily bigger. If your game does not use Pixel Art and you want clean textures, you're more or less forced to optimize your game and graphics to at least Full HD. In your place, I would therefore only use the 1920x1080 variant.