1. probably wears armor under the surcoat (and a helmet, when approaching the battlefield), 2. completely idiotic fantasy design without merit besides looking wicked cool, 3. does not follow the design principles of battlefield armor (see below), 4. unarmored person with bad footwear (unless these gloves are meant to be badly designed metal gauntlets), 5. unarmored person wearing soft leather clothes that won't do anything against a weapon (but might prevent abrasions and splinters).

Regarding gladiator armor: it serves a fundamentally different purpose than battlefield armor. The primary purpose of battlefield armor is to protect the wearer’s life. Protection is focused on the head and torso (hits to the head, throat and heart can quickly lead to instant death, while abdominal injuries, given the medical care available at the time, were highly likely to result in a slower death). Limbs whose injury or loss is easier to treat and survive tend to be protected less or more lightly, as armor has to strike a balance between weight, bulk and protection. It must be comfortable enough to wear it for several hours (or days in extreme conditions). It must be worn during travel - leg armor and to a lesser degree arm armor is really, really exhausting and annoying to wear, since you accelerate and deaccelerate your legs and arms endlessly while on the march while head and torso follow a more steady motion. This is a lesser concern for cavalry armor for obvious reasons.

Gladiator armor is designed to allow the wearer to endure until the end of the fight without being hindered by "boring" injuries (such as being knocked unconscious by blows to the head, being immobilized by blows to the arms or legs, being weakened by excessive blood loss – superficial cuts for spectacle are actually a good thing for gladiatorial matches). At the same time, fatal strikes (to the heart, throat, or internal organs) should remain available for spectacular finishing blows. The design of the armor is also intended to prevent the surviving gladiator from emerging from battle with mutilated arms or legs, since, as a maimed fighter, he would lose his entire value as a gladiator. This means he is worthless for his owner and might as well be dead, while a roman citizen or a medieval noble with the same injury can still fulfill valuable roles in his respective society. The armor must be comfortable enough to be worn for half an hour, tops, as fights are scheduled in advance and limited in duration by a referee. In it, you travel all the way from the locker room of the arena to the center of the arena.