Like other clone trooper officers, Rex was given ARC training. After his training was complete, Rex was assigned command of the 501st Legion's Torrent Company.
Despite his customized armor that greatly resembled that of an ARC Trooper, Rex was a standard Clone Trooper with the rank of Captain. This means that Rex was heavily modified from the Jango Fett template like the majority of Clones and underwent conditioning meant to make him totally obedient.
All clone troopers had to undergo a basic training called flash training. But for ARCs, they would receive additional training directly from Jango Fett himself.
Alpha was the very first official Clone Trooper to be nicknamed, as well as establishing or developing a special training program for having different positions of specially-trained Clone Officers. Alpha trained Clone Officers like; Rex, Cody, Bly and Gree.
ARC troopers had special training that allowed them to act without thinking. They claimed it was similar to the Jedi's use of the Force. Many ARCs were strongly influenced by their trainer Jango Fett, especially aspects of his Mandalorian culture, most notably Spar.
Not more, the same or less. Ranking is not about who's better in combat. It doesn't for instance if that was the case then Rex would've reported to Fives and Echo. Rex was also a ARC trooper but he held the rank of captain.
Highly distinctive, and typically made of sturdy leather, kamas were valued for the protection they offered a wearer's legs from low-flying debris, shrapnel, and against rocket down-wash when worn in conjunction with a jetpack.
Rex was added to the main cast of Star Wars Rebels television series, set fifteen years after The Clone Wars, in the second season. Now seemingly a much older man due to accelerated aging, Rex lives with fellow clone troopers Commander Wolffe and Captain Gregor.
The clone who took the name "Rex" was grown on Kamino like his fellow clone troopers, bred to be among the best soldiers in the galaxy. Rex received additional command training and earned the rank of captain, overseeing Torrent Company within the 501st Battalion.
Captain Rex was only able to resist for a short time. The reason is, he knew about the inhibitor chip and realized that order 66 was exactly what he feared would happen. He still have in and opened fire but not before he told ahsoka to find fives.
Shaak Ti, Nala Se and Fives traveled to Coruscant to present the ARC trooper's discovery to Supreme Chancellor Palpatine in person. But on the way, Nala Se surreptitiously injected Fives with an unknown drug.
Fives tried to convince Anakin Skywalker and Captain Rex of his findings, but he was shot and killed by Clone Commander Fox and the Coruscant Guard before he could do so.
Echo and his fellow Domino, Fives, later helped defend Kamino against a Separatist invasion, and were promoted to ARC troopers after the Separatists retreated.
Rex is often mistakenly refered to as "CT-7567", yet "CT" means, "Clone Trainee" for the Clone Cadets, while "CC" means, "Clone Code" for every other Clone Trooper. The scar under his chin and his character personality is modeled after Han Solo, who was also an officer under the rank of Captain.
For most of the Clone Wars, the 501st Legion was led by Jedi General Anakin Skywalker, Jedi Commander Ahsoka Tano, and Clone Captain Rex, who served as their first in command.
They were often assigned to the same special operations missions, from rescuing a Jedi in an enemy prison to locating a traitor among their own ranks. Cody, though he outranked Rex, trusted in the captain's abilities, and placed him in charge on many occasions.
The 7th Sky Corps was a corps of the Grand Army of the Republic under the joint command of Clone marshal commander Cody and High Jedi General Obi-Wan Kenobi.
As the captain of the 501st, Rex served as second-in-command to Jedi General Anakin Skywalker, whose bravery and unconventionality in battle he came to share.
The “Ahsoka” series is expected to be set around the same time as “The Mandalorian” – almost eight years after the events of “Return of the Jedi,” by which time the Rex character will be a chronological age of 44 and a biological age/appearance of a man well into his 80s (Morrison is 62).
Trivia. Rex is actually 31 years old, though his biological state is likely closer to at least sixty years, due to the accelerated aging that was genetically installed in all Clone Troopers.
The adult clones Obi-Wan saw on Kamino were only about a decade old. That, unfortunately, makes a Rex cameo in Ahsoka difficult. By this point in the Star Wars timeline, Rex would be well into his 80s. Throw in advanced aging, and it's unlikely Rex — or any other clone — would still be alive to make an appearance.
The cold weather assault stormtroopers of the Galactic Empire later wore insulating kamas, as did First Order snowtroopers. The Empire's coastal defender stormtrooper squad leaders wore kamas.
The 327th had elite pilots trained to operate the highly maneuverable Infantry Support Platform. The 327th Star Corps was a corps within the Grand Army of the Republic under the command of Jedi General Aayla Secura and Clone Marshal Commander Bly.
Equipment. Early in the Clone Wars, Fordo wore a lighter version of the Phase I clone armor called ARC trooper armor, which also gave Fordo more protection than its Phase I counterpart. Fordo's armor itself sported red markings.
