So you want your character to be a mary sue with inklings of godhood?
And all classes should be the same?
Wow, is that what you took from what I wrote? I'm not even sure where to start here.
I did say that a class that needs another class just to be barely competent is poorly designed. I also did say that groups should be encouraged to work together, so classes should synergize with each other.
If that means "mary sue with inklings of godhood" to you, I have no idea how to respond to that.
See, as was said, a 10th level party of all clerics (or possibly 3 clerics and a druid) is probably the strongest mechanical party you can make. Swap out a cleric for a wizard and it's still pretty much going to stomp on anything.
A 10th level party of all fighters is monster kibble.
If you don't see a problem with this, then, fine. No worries. I do think this is an issue. You could go two ways with it. Drop down the power of the casters and the monsters so that the mundane classes can catch up. No more size bonuses to grapple, or do away with grapple entirely, no more "needs +X to fight" - 3e did do this to some degree, drastically reduce the number of flying creatures as well as creatures with spell like abilities.
Essentially, turn every monster into a hill giant.
Or, you could go the other way. Go with the idea that this is fantasy and let the "mundane" classes by properly mythic. A 10th level fighter isn't just a really good guy with a sword, he's superhuman. He can do all those mythic things that those guys do - like resist magic that no one else can resist, hold his breath longer than anyone else, be superhumanly strong, take punishment and keep on going with no long term debilitation - that sort of thing.
Personally, I like the idea of the mundane classes being mythic. Legendary warriors shouldn't be regular guys with a sword, IMO. They should be, well, legendary.
