Having actually seen a few Wu Jen in play, they belong in tier 2. They have some quite different cool tricks they can use, and while not quite as awe-inspiring as a sorceror who dedicates his life to breaking the universe (as opposed to actually playing the game), in normal play they will generally out power even an intelligently played Sorceror.
The Watchful spirit and his initiative rerolls are horribly under-appreciated, but the big problem is the relatively short spell list. Wu Jen are better than people think, probably almost on par with a sorc, but definitely not better. Wu jen may get nifty stuff, but Sorcerors get Wings of Flurry/Cover and Arcane Fusion- that's not something you can ignore.
My point is that sorcerors' limited spells known often means they don't have the right tool for the job, but a tool which is sufficiently serviceable. The Wu Jen doesn't have the best tools, but of the ones he has he can know the right one every time. Ie, a wizard's advantages without a wizard's overpowering spell list. I think that makes them even.
Shugenja are crap - their spell list is fucking awful. Tier 5 probably.
That's a horrible exaggeration, especially since we JUST DISCUSSED THEM. yeesh.
Ok, first consider that Shugenja are like Sorcerors, in that they know so many spells and cast them without preparation. Among other things, this means no quicken spell for them (because they don't even have the advantage of a feat to fix this deficiency like Sorcerors do).
They know slightly more spells, insofar as they get an elemental focus and an order, and gain up to 6 spells/spell level in total for 1st level (4 9th level). One of those spells is set by his order. He is also prohibited from learning spells of the opposite element, but they automatically gain Spell Focus with their element (about the only thing they have going in their favor). They cast divine spells.
Ok, the spell list isn't total crap. I was remembering more dd and less awesome (whee illusions) - maybe I'm remembering the OA version? Ok, I suppose tier 3 is probably the right place - they certainly can't compete at tier 2, but they're better than tier 4.
The one thing I really disagree with on your current list is Rogues. Given spell compendium, there really isn't anything immune to SA anymore, and the potion thrower rogue is so clearly better than everything else at your listed tier that either it deserves to be up a tier, or it deserves a tier of its own. Also, factotum's might theoretically hit higher UMD, but that's not all that relevant when a rogue can already do stupid stuff like using a Candle of Invocation to be a cleric of higher level than he is, or drop a caster level 120 blasphemy out of a staff.
You're assuming DM's allow such silly UMD abuse. Most don't. Factotums don't beat rogues because they can UMD better, they beat rogues because cunning surge = I WIN BUTTON against anyone who isn't a full tier above you. Actions are the most valuable thing in D&D. Factotums get more of them.
Also, there isn't anything in SC which makes Oozes un-immune to SA last I heard. Sure, you can get spells that allow you to sneak attack Constructs or Undead or Plants, but casting them takes up valuable actions- the Factotum's already attacked/casted twice.
Last I checked using said wands was a swift action because the spells were swift actions (as per the DMG being the primary source on magic items which says activated items take the same amount of time as using the spell). And the rogue gets to TWF with potion throwinig, and virtually never misses, and adds SA damage.
And its silly to talk about the Tier 1 classes as being uberpowerful if such abuses *aren't* allowed. Clearly the tier 1 list assumes a RAW world. Otherwise every class can be arbitrarily nerfed into evenness.
Even without the stupid stuff, a Rogue can play in a party otherwise composed of Tier 1s and not feel useless. His DPR is high enough he can actually kill things in one round. And he can do a variety of useful (and often magical) things, including stealth, UMD, party face, and so forth; so while he's not tier 1, he's not so far away that he can't play in their games.
A fighter can be in a party of tier ones and not feel useless- someone need to take hits when you can't keep all the enemies away. Tiers are based on power, not party utility. If they were, bards would be at the top.
Except bards aren't even that good in a party of all spellcasters.
"What do you bring to the party?"
"I animated some beefy undead minions yesterday, make myself uberbuff in combat, and can get miracles granted by my god"
"I transform into a powerful creature while retaining all the tricks of my awesome nature spellcasting"
"Say no more, you're in"
"I redefine reality just by thinking about it"
"Check, you're in"
"It makes people a little better at combat."
"Um, I only miss on a natural 1 against monster 12 CRs above our level."
"Err... 14 CRs for me."
"It improves your minions though"
"My undead don't like singing, sorry" (immune)
"My animal companion doesn't miss either"
"My familiar is going to spend the day polymorphed into a beholder and using its AMF eye ray where needed, so I don't see any need for it to 'hit' at all"
"Anything else Bard?"
"Um, I have spells"
"You call those spells? Pshaw! I'll show you what magic is"
"I don't embarass myself with a sword?"
"Scram kid, you're bothering me. Next!"
"Hi, I'm likable McFacey and also Sneaky McSneaky, i spot traps without even trying, and I can use any magic item, so if you need someone to use a wand or something. Oh yeah, and my expected DPR is 200 damage."
"Hmmm... that's not so bad."
"We'll give you a trial run, see how you do."
"Wait! Ugg help you!"
"And what do you do?"
"I hit things really hard!"
*casters look at each other*
"Bets on whether he can kill a Balor? I can summon one for the lulz."
"50kgp on the balor"
Uhm no. A wizard isn't going to turn away a dedicated meatshield. Especially since he can expect to need one sooner or later. The druid and cleric, depending on their build, may not like him, but the wizard will want a pet- I mean, adventuring buddy.
Druid Animal Companion
Animate Undead Minions
Intelligent Undead Minions
Charmed Monsters/People made fanatic with a diplomacy check (nonmagical end effect)
And most of those chosen well outperform a same level fighter, are available in higher quantities, and don't eat xp/treasure shares.
Plus the Druid and the Cleric can take turns swapping as meatshield as necessary.
I'd also list cohorts, but you take another full caster as your cohort when you get leadership.
This idea that a player has to play a meatshield, or its even desirable for them to do so, is a myth, and should be treated as such. Even in standard play, the meatshield is superfluous by 9th level because the monsters just ignore him and move around/past him, so the wizard has to have his own solutions anyway.
Now, a fighter with ranks in profession(bartender)... well, they may at least find out where he works at night. "Martini, shaken, not stirred."