Help me save this basil!

I was growing 4 lemon basil plants in my Aerogarden and I decided to transplant them into a single pot together about 4 days ago. They seemed fine the first day, but they are quickly wilting and dying. I was careful with the roots, but the root systems were definitely pretty long. What's interesting is there appears to be new growth on the stems, they're just very small right now, though a couple stems look like they're dead or dying.

Is this a case of root shock, too much water, or just finicky plants? Should I removed all the leaves and let the plant focus on new growth?

Open to thoughts and suggestions! I have a few sweet basil pods sitting in my Aerogarden that were headed to a pot soon, but now I'm hesitant.