I've never used Throgg so can't help much on that list, on the first one however....
Warptide wrote:
Winds of Change
2,498 Warriors of Chaos
Comp: 12.6
LORDS
Sorcerer Lord
-Level 4, lore of Tzeentch, mark of Tzeentch
-Third eye of Tzeentch, chaos familiar
-Talisman of Preservation, dragonhelm
-Mounted on Disc of Tzeentch
The chaos familiar isn't your best option on a lvl4 wizard, since there is a high chance that you will know the spell you want and knowing a 5th will only make it harder to cast with the winds of magic rolls. I'd take a dispel scroll instead at 2,500 you will surely use it against other armies. Also I'd put the enchanted or charmed shield here since he will be flying solo and I'd rather have a 1+ save or discard a cannon ball on a 2+, after all this is your most expensive unit in the list, losing him will hurt on the points.
HEROES
Exalted Hero
-Battle Standard, Mark of Nurgle
-Sword of might, enchanted shield, opal amulet
Exalted Hero
-Mark of Nurgle
-Sword of anti-heroes, charmed shield
-Juggernaut
Exalted Hero
-Daemonic mount w/ barding, shield
-Sword of strife, dragonbane gem, ironcurse icon
Chaos Sorcerer
-Lvl. 2, lore of Shadow
-Skull of Katam, chalice of chaos
As mentioned above the nurgle hero can't take a juggernaut so... assuming it was a
MoK hero I wouldn't send him solo, without a ward he will be an easy prey and probably fall before he can get into combat, the main problem with the solo units is that they are great to hunt monsters or warmachines but not so good to fight units because of the resolution, you'll have to do really really well to not lose combat if facing any decent sized unit. I'd drop the jugger hero.
The
BSB is ok I guess, I've never tried the opal amulet, but if you are going for it I'd get scaled skin and fencer blades instead of the sword of might, most enemies should be hitting you on 6's and with a 2+ save you should be able to hold on that one use 4+ ward. Still I think it's an expensive loadout for a 2W model. I'd keep it simple and just get
MoN, scaled skin, shield and ironcurse icon, getting hit on 5's 1+ armor save, 6's parry save.
On the daemonic mount hero, give it
MoT, armor of destiny, halberd, shield and burning body. He would get a 2+ armor save vs range and 3+ armor save in close combat with a 3+ ward. The +1
str and flaming attacks will be great to deal with nasty monsters like the skaven abomination, of ogre cannons with regen. Hell if you get some "free" points getting soul feeder on this guy could be really nice, doing 4 S6 hits, followed by 2 S5 and a stomp give you lots of chances to roll a 6 and get back one of your wounds
The lvl2 sorcers is ok, I'd take the familiar with him instead of the skull of katam thou. Knowing a 3rd spell in shadows is great and I love the chalice it isn't one of the best items but I take it on my sorcerers/heroes whenever I have some free points, you never know when a
DP will appear to save the day
CORE
20 Chaos Warriors
-Mark of Nurgle, hand weapon, shields
-Full command, banner of swiftness
40 Chaos Marauders
-Full command, shields
-Mark of Tzeentch
2x 5 Warhounds
I'd drop the marauders and get the 2xChariots from your 2nd list instead.
SPECIAL
5 Chaos Knights
-Musician, standard bearer w/ Blasted Standard
-Mark of Tzeentch, ensorcelled weapons
The knights are really expensive and 5 won't really make much of a difference, the chimera and gorebeast from your 2nd list would also be a lot more threatening
RARE
Hellcannon
The hellcannon is fine, it is pretty random which is nice with chaos, but I would rely a lot more on the 3 skull crushers everytime, I didn't make the maths but with some of the cuts on the other section you might be able to fit both the hellcannon and skull crushers
mean green fightin machine 
)