The Kaminoans created a massive clone army for the Republic to use. But just because they made one clones doesn't mean that all the copies were going to be the same forever. As they went along, they refined their process and the training that the clones would receive, resulting in the Phase II trooper, of which we get a preview here before they make their way to Star Wars: Legion tabletops.
From the post:
The Galactic Republic’s clone troopers are some of the finest soldiers the Star Wars™ galaxy has ever seen. But even the best troops can be limited by the equipment they carry—and wear—into battle. To get the most out of its clones, then, the Republic gradually replaced the uncomfortable armor worn by its earliest batches of clones with a more advanced design that helped bring out their individual strengths.
Not only did this Phase II clone armor allow for Republic forces to use advanced tactical gear in the field, the clones wearing it were more prepared for the rigors of battle. Soon, you’ll be able to supplement your Republic armies with this new generation of clone troopers by picking up the Phase II Clone Troopers Unit Expansionfor Star Wars™: Legion!
Within this expansion, you’ll find everything you need to add an elite new corps unit to your Galactic Republic armies. Seven hard plastic Phase II Clone Trooper miniatures stand ready to meet any enemy on the battlefield, including a Phase II Z-6 Trooper and a Phase II Mortar Trooper that can be customized in several ways.
You can choose to assemble your Phase II Clone Trooper Leader and Z-6 Clone Trooper with or without their helmets, and the Z-6 Clone Trooper’s heavy weapon can be replaced with the standard DC-15A blaster rifle to add even more variety to the look of your army. Finally, you can build your Phase II Mortar Trooper with the mortar stowed on his back or deployed on the ground, as well as with his visor up or down.
Read on to see more of what to expect in the Phase II Clone Troopers Unit Expansion!