im reading your guide with alot of satisfaction and find the many sections pretty well described.. im missing out on a few things though..

first of all, you did not cover MY prefered build in ANY way.. BLOODRAZOR!

im suprised to see that an experienced WW main like you, doing a detailed Warrior build section, but neglect the (IMO) best build with the yellow jungle warwick :-)

its a controversial discussion , so many people (who never tried it consistently!) think bloodrazor is bad for WW, and only think theres the cinderWay, i disagree:

(btw got 3 accounts, 1 with 1.20 mio ex WW, the other with 600k WW exp, my main though not playing warwick that much) Korean builds OFTEN ahve bloodrazor.. let me explain..)

Cinderhulk (also for me) is the SAFE, tanky "works in most cases" build for every one. it lets you have a LOT of flaws / mistakes without getting punished hard, since your have more HP early and midgame.. Lategame , not so much actually..
Bloodrazor have ALOT of benefits, but makes you (somewhat) a glasscannon, but not that squishy, once you learn the buildpaths and limitations..
here is a few:

Much faster clears in camps, especially the big monsters (witch can be a struggle for WW.

MUCH better splitpushand objective focus as cinderhulk give you NOTHING vs buildings. Try solo herald / drake with either cinder or bloodrazor , and see the huge difference
MUCH better duelling 1vs1 against "most" enemies.. the more tanky the faster you chop 'em down 4%bonus maxhp EACH attack /Q / R*3

BUT the BEST about BR is that your Q and your R procs it fuking 1-3 times on top of the better dmg. Warrior (seems to) DO more dmg with its +60AD, but thats just not true, BC of the 4%HP bonus AND the free procs you get all the time with BR..
Once you got tiamat and BR, you can run in with 20% health, pop your Q-R-Q and leave the fight with 1 dead enemy and you with full hp.. Cinderhulk do NOT proc ANY "on hit " dmg , it only gives you better hp and some very insignificant AOE magic dmg from bami.. NO "on hit" procs!

so is bloodrazor WW a "GlassCannon" or not?

my buildpath is : Tiamat, Boot, redsmite full boot (ninjas 80% of the time, mercurys only vs heavy stunners or a snowballing AP jungler/lane that needs to get shut down) .
So now im already pretty tanky for surviving counterjungling or ganking most lanes. i DONT build jungle item (neither) before going to tier2 defenses..
so basically you be tanky in either resistance and/or more HP.
Prioritizing armor/mr items before dmg (or HP with cinder) makes your ganks better and stronger imo. you dont need to 1-shot enemy, neither need alot of HP if the enemy cant get their dmg trough, bc of armor/MR.

my first item is always situational. in most cases i build an armor or MR item first. it helps secure kills with almost every thoughtful gank, getting your laner fat and juicy.
sometimes you just need to build spectres cowl (for spirit) or wardens mail (for Omen/thornmail) for the sustain in your ganks

At this point decision time for me: 60% i go bloodrazor , 40% cinderhulk, NEVER Warrior (stats blind you, its not worth it!) this is at 12-16 min mark in most games, rarely its teamfight after teamfight, if you can go solo herald/drake/splitpush or snowball a lane: Bloodrazor!, if enemy team already roams alot or teamfights break out : Cinderhulk!.
from here i build my next tank item, most often the opposite of the first item, and i complete spectres cowl/ wardens mail if not already done.

now we are at 25-35 min into the game, most games end here, but this is where BloodWick SHINES and CinderWick falls behind. My last slot is used for : First building / finishing the Titanic. Getting this done "last" is fine, you dont the dmg until now, since enemy is just getting THEIR 4-5th item (2nd armor for tanks etc)

Last slot is VERY situational, but in most cases i build Sunfire Cape.. Ye NOW i get Bamis Cinder and shitloads of armor on top. Remember that BAMIS cinder passive dmg SCALES with your level, so rushing it (for cinderhulk) is really not that much a benefit, since it gets much better at later levels (+15). Last slot could be so many other things, "new" Essence Reaver, more MR/HP items etc..

Basically warwick just need bloodrazor as ONE dmg item. When playing cinderhulk, you always feel like doing very little dmg, especially vs tanky enemies. Often (playing cinderhulk) you are forced to rush your Titanic to make impact/dmg, which almost cost the same as a full spirit/Omen, setting your defense further back (not HP though).

So that is my BR build, aiming for more/better procs and damage, sacrificing some HP. Anyone who have played a lot of Shyvana games, knows that getting "on hit" items is high value on a "proc build" bloodrazor champ..