Umm ... after picking myself up off the ground at the description of the "High Warrior Monk" and "Warrior Mage" as onl.y being "verging on overpowered" ...
Well, we'll just have to disagree on that one, I guess.
In regards to the Warrior Mage, they can certainly be quite powerful, no doubt about it, and yes, they have great spells... but they also need high stats to have the Dev. Points to buy them, and at the same time they have to max out a number of other skills to be viable in combat. In short, they feel a 'Dev. Point crunch'. They have a semi-spell user's costs for weapons (i.e., not particularly low) and their costs for directed spells are significant as well. On top of that, they have substantial costs for Body Development, and need to keep Transcend Armor maxed as well (and it ain't cheap). All of this makes their Dev. Point crunch even crunchier.
Example: To max out one weapon, Body Development, Transcend Armor and one Directed Spell, a Warrior Mage has to spend a staggering 35 Development Points. Assuming he HAS 35 development points to begin with, he won't be training much in other vital areas: he might, if he is lucky, be able to buy one rank in perception. He certainly won't have much left over for maneuvering in armor. I hope he doesn't fall into a river, because he won't be able to swim. And he hasn't yet bought even a single spell.
Furthermore, depending on how you use Transcend Armor, the Warrior Mage can be very short lived. In the core rules, as Rasyr noted recently, you have to go ahead with your spell even if you fail your Transcend Armor roll. Fail even a moderate Transcend Armor role in the middle of combat and if the ESF roll doesn't kill you, your opponent probably will. This is a major limitation on the effectiveness (and lifespan!) of the typical Warrior Mage.
So yes, the Warrior Mages come into their own at later levels and become very powerful... but the campaigns I have rarely go beyond level 11 or 12, so this is rarely a problem. I had two characters play them and they were fine. They have a great range of spells and are definitely powerful, but they are spread very thin and have to wince every time they try to cast a spell in combat.
The High Warrior Monk is, IMHO, balanced because the 'Warrior Monk' and to some extent the 'Monk' are rather underpowered. Simply put, the costs for Martial Arts are generally too high in the Core books (mainly due to the fact that Martial Arts are split into four ranks). The fact that the designers felt the need to include the 'High Warrior Monk' in the first Companion seems to be a recognition of this fact. The high costs for Martial Arts makes the original Warrior Monk a bit of a problem: yes, he has some nice abilities and can do backflips, but he has to pay 16 Dev. Points just to be as good in his primary attack as a fighter is in his-- yet the fighter pays a whopping 10 less Dev. Points. The same problem makes the Monk rather sub-par (despite great spells and adrenal defense) compared to some other semi-spell users.
I don't know, maybe your games are different than mine... but I've had several people play Warrior Mages and High Warrior Monks, and they seemed to fit right in alongside the Fighters, Clerics, and Magicians. The one time I had someone try to play a Monk, he was rather clearly underpowered compared to the other players, and I felt badly for him. I'm not saying you can't make a decent monk or warrior monk... my first Rolemaster character ever was a Warrior Monk, and I still love him dearly... but those Martial Arts costs are killers. In my experience, after years of playtesting, I've had virtually no problems with the Warrior Mage or the High Warrior Monk.
But if they don't work for you, that's fine with me; don't include them in your campaigns.
Cheers