If you are using IG-88 Poe is still a good option. Perhaps with Jawa/Datcha also. Outside of that he probably doesnt need to be on your team anymore (since the nerf/speed change). You just lose a lot of options/damage by forcing him in.
Han is spectacular with ackbar. He can also work in other setups... But you really have to try hard to make it happen. There are plenty of better choices. If you can find a team he works with (like rebels) he is a great TM manipulator though.
RG is undoubtedly the best tank of the 3 now if defense is what you need. No competition. He is miles better than the other two at protecting your team. He will fit in most teams and perform his duty as expected, the other two need specific setups to be effective. So RG is better overall. Horrid farm though.