The title pretty much says it all but I'll add a few points why in my opinion the Rages currently have way too many advantages.

1. First of all, training and maintaining a Rage is significantly easier and cheaper than War and Theatrics.
- The training itself requires mostly Strength and Chi, Intellect is needed only for the weapon, Barreling Attack and Sunder Armour out of which you really need the weapon and Sunder Armour. Hence, you can afford to buy dumb but otherwise very fit slaves for Rages while the would-be War and Theatrics slave has to have some brains or his/her traning will be a nightmare. Intellect is not a combat stat though so the points allocated to it are subtracted from the combat stats, i.e. it's pretty difficult to find a smart slave with excellent combat stats while it's fairly easy to find a dumb one who can perform more than well otherwise.
- Once bought, a Rage gladiator is significantly easier to maintain than the rest. You can equip him/her with green gear only and he/she'll perform just as well and usually better than a purple-clad War or Theatrics until he/she reaches the highest brackets. The reasons are below.

2. Second, Rages have all the skills they need to perform very well in their own skill tree. I've seen a few Rages with Feint but that's all. War and Theatrics very often go for skills in the other trees to remain competitive (the number of Last Stand Wars for example seem to be increasing by the day) and the highest level skills in their own trees thus become unreachable + the higher level skills from the other trees are obviously more difficult and time-consuming to reach than the ones from their own. The quality of the said high level skills doesn't seem equal too. War's entire fifth row is useless, maybe with the exception of Master of Arms, which is however more interesting than practical and Battle Hardened is very tough to reach and involves investing in sub-optimal skills. Theatrics has a good fifth row with Knockout and Heavy Scarring (I guess the latter adds additional armour or defense) but Second Wind is totally useless, given that the fights in the higher brackets rarely take more than 2-3 rounds - except maybe if heavily armoured opponents are fighting with knives. In comparison, Rage has a very nice (and, as mentioned, very reachable) fifth row, particularly Shock & Awe and Overwhelming Presence and a decent ultimate skill in the face of Total Carnage.

3. Third and possibly most important - the access to Berserk. No other class has so powerful unique fighting style. War's Tank is situational and the defence bonus that it gives is certainly not enough to stop a determined attacker and, of course, it's a self-damaging style due to the "dissatisfied crowd". Counterstrike is just as situational, although more widely employed, and by no means guarantees a victory. That's not the case with Berserk. It gives a truckload of additional offensive power - quantitatively and qualitatively - at the expense of the defence which the Rages don't have anyway and somewhat faster tiring but not even close to fast enough to be worth mentioning. All Rages which are not totally clueless start with Berserk from the beginning of the battle and end it long before the negative effects of the style can be felt - and usually before the opponent can even counter-attack. Using Berserk is a no-brainer, it needs no strategy to be effective and overpowers all other fighting styles (especially combined with Rage's own skills) at no cost. That's cheap and boring. I have a 2H Rage in Legends with 80% win:loss ration and I'm considering selling her because she's the most boring of all of my fighters despite her great performance - two to three strikes in berserk mode and the opponent is down, only Rages with Last Stand and 10+ levels stronger Wars and Theatrics with blue and purple items tend to beat her from time to time (and it's not like that I'm spoiling her with purple gear, not at all - just one blue sword and everything else green).

4. Due to 3., Rages essentially use only 2 fighting strategies - Berserk as their Start of Fight and a Last Stand trigger in case the opponent somehow manages to get them to low health. This makes their management too easy, straight-forward and... well, boring (yeah, I know that some will disagree about the last one but that's my opinion). I guess some of the top level Rages use additional strategies against other Rages but from what I've seen, they never bother with more than the above mentioned two against War in Theatrics. I don't think that the other two classes should be forced to employ their full arsenal of tricks while the Rages have access to some cookie-cutters and abuse them all the time.

In the end, I'd like to mention that I've gathered these impressions from both my own Rage gladiators and watching the fights in the higher brackets + the Blood Games. I've seen Theatrics beat Rages occasionally but the opposite seems more frequent and War vs. Rage looks like a totally unfair fight for the War, except if he/she is some Trug with 2000+ health fighting against much less durable Rage. My own Wars and Treatics could say the same. So, what say you