Surprisingly CG looks to be one of the best in anime I've seen so far. But that's all I find good about this, because the rest is pretty far from history. At least as per what I've read in my days and if you apply some logic.
Cestvs has quite a strange physique. We see that he is a slave, but his body is that of a soldier, but with very narrow shoulders (heck, I think even mine are wider). Narrowness can be explained by him being a slave, and having bad nourishment, and training (if any) not caring about the shoulders. But the rest... The thing is, slaves rarely got any special training in the first place, unless they were gladiators (more on that further), that helped bring in money (surprisingly Spartacus TV series showed that quite accurately). Thus a regular slave would not get such abs: it would be the reverse, because of how our bodies work (tendency to store fat and eat muscles in case of low caloric intake).
Furthermore the boy is too pretty and somewhat girly even. He would have been sold as a sex slave. That would make much more sense than that stupid BL moment in the beginning of the episode (not hating BL, it was just completely out of place).
Padded gloves. Well, yeah, they could be used in fist-fights (not sure they could be considered boxing as per current standards), but I doubt they would be used in mock fights. Why? So not to spoil the merchandise, duh. Also, consider, that that is a weapon. So the process would be to isolate fighters from real thing as much as possible.
Why a guy who was not even taught to brawl selected and allowed in the fight? Despite what some may think people of the yesteryear were not that stupid. Trainers usually were slaves as well and if they did not provide a good fighter they could get punished or even killed. Not training a boy to brawl is an invitation to murder. At the least he could have tried talking the masters out of it.
So, if you are into fist-fights, you may try watching this. But if you are into ancient history - better watch Spartacus: while it's far from perfect, it did a good job with some finer details, that made it more believable.
