Okay, this is really a list for something after Legacy, and I'm sure I posted it before on the old board, but the latest "The Basics" reminded me. Let's say go!
Esmeral, with a pretool for Deathsaurus, with robot, mecha-kaiju, and a combiner torso mode. Doesn't need to be CW-compatible, but will need to combine with most of the rest of these. Esmeral comes with 2 dinosaur-themed Battlemasters, Deathsaurus gets his Tiger and Eagle as Battlemasters.
Lyzack, with a Leozack pretool, and Jallguar, with the ability to combine into a combiner torso, and appropriate Beast Battlemasters.
Kakuryu and Rairyu, with the ability to combine into a combiner torso. Dino-altmodes, and Dino-themed Battlemasters in lieu of Dino-Shells.
Gaihawk, Hellbat, Killbison, Drillhorn, and Deathcobra, with Beast Battlemasters. Each can turn into the appropriate combiner limb.
Goryu, Gairyu, Yokuryu, and Doryu, with Dino Battlemasters. Each can turn into the appropriate limb.
Road Ceasar is a little trickier:
Blacker/Gripper needs to form a combiner torso, but can't really be much bigger than the other two.
Laster and Braver form the legs (and maybe part of the lower torso?).
The Rescue Patrol is resized so that 2 of them can combine to form a combiner arm, thus combining with the Brainmasters to form Road Ceasar.
Now, if we get this far, this is where things get crazy:
Leozack or Lyzack, Jallguar, Killbison, and Drillhorn get their Rescue Force decos, as themselves, having switched sides. They would be able to combine with the Rescue Patrol or a "rebuilt" DeathCobra redeco to form Big Rescue Force.
Similarly, some or all of the Dinoforce would get Heroic redecos.
Finally, Deathsaurus and/or Esmeral get a Heroic deco. The war is over. The Transformers achieve Victory.