The fool is easy - use his aspects to drive his "luckiness"... get table permission to drop a skill or two, in lieu of some very vague aspects about his role. I'm not familiar with the characters you mention, but I know the type.
- Concept: Everthing Goes My Way
- Trouble: don't know nuthin bout nothin
- Always Finds the right tool for the job
- Just plain lucky.
- I can always find help.
Always find the right tool for the job: The advantage is obvious - spend a fate, get a +2, and narrate finding something useful. The drawback is that sometimes, you can't make use of that right tool. Or you won't settle for the wrong one.
Just Plain Lucky: The drawback - skill's what's needed, and this zeppo doesn't really have it.
I can always find help: the drawback side is "sometimes, I need more help than I got" or "For once, there is no help!"
The guy who does horrible things well is again defined more by aspects.
- Concept: I'm the unpleasant force that can't be stopped.
- trouble: I'm dangerous and scary.
- When the situation is grim, I'm your man, especially if I can make it grimmer!
- Make it hurt to make it work...
- That scary kind of Crazy
The concept is dual edged due to it providing plenty of room for compels... scare off the target, or won't back down.
Dangerous and Scary likewise is useful at times, but also is the warning to others.
Make it hurt to make it work: this is where it turns him into the scary psyhco. If he can do it painfully, he gets to invoke for bonus. But also, it's useful against him - He can't find the right source of pain for the situation. Or there's no pain involved, so he's not into it.
The chump is harder to do.
- Concept: I am an incompetent boob.
- Trouble: Things go south around me.
- I can only help
- Lovable but inept.
This guy is best as an NPC, or as a sidekick.
Note that he's best as an invoke against the rest of the party.
Or by the rest of the party.
Remember, you can use other people's aspects.
I can only help: can be used against him when he does stuff, but can be used by others to provide them access to another aspect when he's present and willing.
Lovable but inept: again, great for compels on his friends.