Top end of tuber produces sprouts. Bottom of tuber produces roots.

Is the root system large? If the tubers are to go in a 2"- 3" of soil (which was recommended to me) will there be enough room for the roots

If you are starting them inside, in pots, with plans to move them into the ground when it warms up, then planting them shallow to wake them up and get a head start is fine. You will plant them deeper (6") when you move them into the beds. If you are planning on keeping them in pots then you need to either plant them deeper, or plant them shallow in a deep pot and add soil as they grow.

So yes 2-3 " of soil is enough if they are only in there for 3-4 weeks