I see it this way.
Situation:
Party has to get into a castle surrounded by a bunch of thugs, stop a wedding, kill a count out of vengeance, and quickly escape alive and (hopefully) intact. All in the space of 30 minutes.
Resources:
- A really huge strong guy with not a whole lotta wits.
- A really good swordsman with some wits, but not a whole lot.
- An even better swordsman who in the past whipped both the other guys in their respective fields, but is now paralyzed from the neck down and very slowly recovering. Has a whole lotta wits.
- a wheelbarrow
- a cloak of fire resistance
- a candle
- knowing about a very famous and terrifying raider who leaves no survivors
Plan -
Half-dead smart guy sets an idea for psychological warfare. Big guys stands in wheelbarrow with cloak draped over him, covering wheelbarrow. Gets set on fire. Swordsman wheels him forward towards assembles thugs. Big guys screams that he's the famous raider, and there will be no survivors. Thugs run. Big guy will kill gatekeeper unless he gives them the key. Gatekeeper gives key. Party enters castle. They run into four guards and the count. Swordsman dispatches guards while strong guy holds up smart guy. Swordsman challenges count. Count flees. Swordsman gives chase. Swordsman runs into locked door. Strong guy sets smart guy against wall, breaks down door for swordsman. Swordsman chases down count, gets stabbed a few times, kills count. Smart guy can't stop the wedding (which is a farcity, really, and doesn't count as a marriage), but out-bluffs the groom with his fancy smarts, and escapes with the bride out into the courtyard, where the strong guy has found a horse for each of them. They all escape. The end.
In summation:
Now, from a D&D standpoint. The smart guy was already really good at killing stuff and being smart, but in this case he had to use his smarts. he came up with the plan to scare off the thugs, outwit the groom, and escape with the pretty lady. Smarts-based EXP. Strong guy helped scared off the thugs, helped get the count, and provided escape mounts. All-around EXP, but not that much for smarts. Swordsman helps scare off the thugs, kills a few inept guards, and kills the count. Mostly combat-based EXP, a few for smarts. The tactics and planning group was able to think it through, kill a few guys, accomplish the goal, etc. Fun, yay.
Now, if they had charged in and flailed big arms and sharp swords, they would be slaughtered and not accomplish their objective. End of game. No exp.
The combat-minded group would have had fun killing a few guards, and have good characters to remember, but the game would be over. Time to roll up new characters and start up a new game. Fun, yay.
My idea: have a exp progression for combat & spellcasting, and another for skill use. Success in combat lead to combat exp. Success in skill use adds to skill exp. Follow current leveling guide, but divide it up as you like.
END RESULT : The system works, but If you don't find it to your tastes, use a different system. Or design one for yourself. D&D is a mostly combat game that can also be good for role-playing, if all involved are capable and willing. You want more of a universally role-playing centered game, play with a different system. Exalted is nice.