I have ran and tested all of those shoes. There isn’t much difference between the Tangent 3 and the Fastwitch 2 or 3. The original Fastwitch was a lot different. You would do fine racing in the Fastwitch 3s as they have a nice midfoot bridge and mild rearfoot post like the Tangents. They fit the same, so no need to downsize. Actually, I find the Tangents a little wide in the forefoot with their new, open mesh.
The A2s are a VERY minimal shoe compared with either of the above and should be relegated to 10K or under for most “pronators” (your words) although you “could” run a marathon in them if efficient. Certainly not a shoe to train in.