My guess is that they would fare very poorly as iconics. And the higher level, they got, they worse they'd fare.
Why? There isn't a single straight-up spellcaster in the bunch. All of the spellcasters are at least two levels caster levels behind where they're expected to be and most of them are actually behind by three or more. Which means that they'll still be throwing single magic missiles when fireball is expected, flaming spheres or 4d6 scorching rays when they are expected to have Phantasmal Killer, and will just be latching on to Prismatic Spray or Holy Word when they're expected to have Meteor Swarm, Shapechange, Gate, and Miracle. Instead of having a 60% chance to penetrate their foes SR with Greater Spell Penetration, they'll have a mere 40-50% chance. And, since they're all splitting their stats up more and are gaining strengths other than spellcasting, they'll be less likely to have Spell Focus or DC increasing abilities so their foes will make their saves more often.
Also, since their caster levels are lower, despite each individual character having more options, the party as a whole will have fewer options. Sure it's nifty when 3/4 of your tenth level party can cast fly but compared to the group where one party member can cast teleport or Shadow Walk and another can cast Wind Walk, you've actually got fewer significant options.
If they have advance notice of a fight and have the opportunity to buff up, they'll excel but in most normal situations, they'll lag significantly behind the single-classed party in terms of effectiveness.
Now the interesting thing is that I don't think they're weak prestige classes. The Arcane Trickster can work well in a rogue's role. And the Eldritch Knight can fill the role of a fighter and backup arcanist (but don't expect him to do well with high powered offensively oriented magic). The Shadowdancer adds a lot of abilities to a rogue. Of course, I actually do think that the mystic theurge is generally weak all-around but it can probably be made to work as long as the player realizes that it's a mystic theurge rather than a cleric, a wizard, or a cleric and a wizard in one. The problem is that, by combining all of the partial progression spellcasters into one party they end up forced into roles they aren't suited for.
This is not to say that it wouldn't be a fun party to play in or that it wouldn't make a good campaign. However, it's not suited to the same challenges as the iconic party is and such a campaign would need to deviate from some of the standard, iconic assumptions in order to work.
The other suggestion (bard, barbarian, druid, ranger), has more potential as an iconic party.
Tallarn said:
I was wondering, with the new PrC's in the 3.5e manual, how well this party would do in comparison:
Arcane Trickster (wizard/rogue)
Eldritch Knight (fighter/wizard)
Mystic Theurge (cleric/wizard)
Shadowdancer (fighter/rogue)
My guess is that, like most things, you'd be giving up sheer power for more flexibility. It'd be an interesting experiment, though. I guess that at low levels the more specialised party might have the advantage, but at higher levels I think the second group would have the advantage. They're tough in a stand up fight, but give them time and they're incredibly nasty. I would imagine it'd be a bit of a headache for the DM.
What do people think? Which party would you rather play in? Which would you rather go up against? Also, feel free to substitute other multiclass style PrC's if you want.