Depending on the maneuvers and what you are doing, you may get your butts kicked either way. Training in cunning defense helps a bit and training in the specific maneuver being used against you helps more but as a ranger there are only so many maneuvers that you have access to. There are also really only two situations where combat maneuvers are really a problem for people, bandits or grimswarm. So, which is it for you?

In both cases one thing that will help a lot is having your physical defense high enough to survive being maneuvered until you recover and can hit back. If you guys hunt with each other often one thing that may help is oak/unstun wands, just get enough MIU to use them reliably

<One point of view: We've been getting our butts kicked by cmans more than AS attacks>

One of the most significant factors to both of these skills that I have found with rangers is Encumbrance. Making sure your unecumbered before even casting Pheons, or strength will go a long ways to maximize the training you already have. Many rangers take advantage of there strength spell and keep it up all the time, but they neglect to check when it is not up to see if there actually as light as they think.
Another factor that will help greatly with maximizing what you already have, buy a helmet. Find a light weight 4x metal helmet and keep it in your bag, wear it when you know your hunting where cmans may effect you. I would try both of those before making any training choices. The cmans that get me the most are headbutts, garrotes, and stun maneuvers, all are head related.

The 4x helmet does not offer any additional enchantment over the brig. The brig is rigid leather, in theory.. If you wear a helmet of a stronger material such as a vultite one, the potential damage to head specific attacks would be reduced better then the leather. I think in the case of some cman attacks, it can defend against them (like headbutt or subdue) but that I am not positive about. I do know the level of a success can be reduced, just as throwing on an aventail if your going where things garrote/neck attacks will aid in reducing that moves success. That I know works, I do that with gremlins and see a clear change in there success rate.

With some of the newer changes it probably needs to be retested, but that is basically what misc. armor is for, be used for specific purposes or protect specific areas better. Now of course with enhancements it has another purpose.

The encumbrance thing is probably a larger issue. Currently I am slightly encumbered with no spells, and I am getting spotted left and right by the critters in lich town even with spells. When I am not encumbered without spells I rare get seen after getting spells. If your starting your hunt already encumbered before spells, the spells may get rid of it but you basically still not at your best in anything that encumbrance effects.