Two USB-A ports would barely fit next to each other width-wise, but wouldn't provide enough space to actually plug in two USB-A cables/devices at the same time. Most cables have plastic covering the connector that adds 0.2-0.5cm of width. Grab two USB-A cables and place them right next to each other and you'll see a gap.
Edit: plus you need to add 0.1cm for the plastic housing of the adapter itself.
Edit: plus you need to add 0.1cm for the plastic housing of the adapter itself.