Advice on Fixing a SQL 2016 AG Setup

He guys hope you can help me out with a AG/Cluster setup.

Currently I have two SQL Servers (2016 Enterprise) hosting 2 Availability Groups. The setup is a bit convoluted with the 1st node being the primary for the first AG and 2nd node being the secondary, while the 2nd node is the primary for the second AG and the 1st node is the secondary (don't ask why this was setup this way).

I want to set it up properly and I got 2 new SQL boxes setup and I am ready try to untangle this mess (there are some performance issues when fail-overs happen).
Now the question I have is what is the best way to go about this.

The first options I have is to add the two new servers to the WFC that is in place and than change the secondaries for the two AG to the new servers so that 1st node would have its secondary on the 3rd node and 2nd node would have its...