Ok..Lets try to look at this realistically in a Fantasy setting. I know it sounds crazy *cough cough* but bare with me a moment.
Who do you think would be more powerful on a battlefield?
A. a dual kopesh wielding Halfling with fighter training
B. a highly experienced Sorcerer
c. a donkey with a +5 mithral full plate
D. all of the above
If your answer was A. a dual kopesh wielding Halfling with fighter training. This is a formidable force but you are not thinking this through to its entirety.
If your answer was B. a highly experienced Sorcerer then you must know that magic would be the most powerful force on the battlefield as even the best weapons and fighters are are enhanced with this but they would not come close in power to a caster of magic. However this not necessarily the right answer either.
If your answer was B. a donkey with a +5 mithral full plate then you are drunk much like myself but this would be the best answer thus far.
If your answer was D. all of the above then you have answered correctly. Even though the Sorcerer is more powerful than the Fighter and they are unbalanced individually true power and balance comes with the skills and tools of experience. The balance is in the plan of attack and the cohesion in the party and being thus, even the donkey with a +5 mithral full plate can be a hero.
just having some fun mates__cheers