I remember one time, somebody described WoC to me as having absolutely dominating statlines with the capabilities to win practically any straight-up fight, but lacking the diverse tricks and aces-up-the-sleeves that other armies have. If this is accurate, it would mean that there's a whole new layer to strategy for the WoC because due to the fact that they lack the usual tactical layers of other armies, a good player needs to primarily focus their tactics on getting into those aforementioned straight-up fights and prevent opponents from pulling their ace up the sleeve.
Any truth to that?
That used to be true, back when WoC did not have the shooting or fast attack options that they have now. currently based on straight up stats they crush every other army, combined with additional options that synergize better than most other army options and you get a truly elite army. with an awesome stone thrower, fast Calvary and monstrous Calvary options and very decent magic WoC no longer have any flaws, they have access to more tactics than lizardmen and can answer any threat from any other army easily. I consider them to be balanced but at a higher level than other armies, they are by no means unbeatable but all things being equal a WoC army against lizardmen in the hands of equally experienced players will win probably two out of three times easily.
WoC are indeed a powerful army, I would never deny that. I would agree that they are definitely a top tier army... however they are not the only army residing in that top tier. There are difficult match ups for WoC as well, especially the pesky Elven armies. Skaven can also give WoC a good challenge as well as Ogres, Daemons and Dwarfs if the players are of equal skill level.
I agree with Bainbow the tactics of WoC are primarily to counter the tactics (aces-up-the-sleeves) of their opposition. For instance, in a straight up battle WoC will top Lizardmen fairly easily. However, Lizardmen have the tools to win the chaff battle and thus avoid a straight up battle and fight on their own terms. The WoC player has to counteract this. As an example, Skullcrushers can beat almost anything thing in the game one to one. But a skilled player can make use of their frenzy to neutralize them. As a result it still requires a huge amount of skill on the WoC part to take on a skilled player of another army.
A quick breakdown of WoC...
Characters - Extremely elite, some of the best in the game, but expensive. Have you ever seen what a scroll caddy costs in a WoC army? That said, no complaints!
Shooting - nearly non-existent, unless you opt to take the Hellcannon, marauder cavalry are inconsequential. I love the Hellcannon personally, but I know a lot of WoC players who do not like it at all. The Hellcannon can unleash huge amounts of devastation, or do nothing at all. It is very hit and miss. Also, the more points invested in Hellcannons the less rare points are available for skullcrushers.
Magic - mediocre. There are many armies that are far superior in terms of magic due to the availability of magic items, special rules or the cost of purchasing wizards. The advantage of WoC is that the wizards are durable; but this durability comes with a significant price tag (see scroll caddy comment above).
Movement - WoC can have an extremely mobile army if they wish to go that route. They have lots of quick units and an abundance of flying options. Once again though, they have to pay a premium for it. But a fast WoC army can be extremely potent!
Close Combat - this is where the army really shines. This is our bread and butter. Best of the best. Only a few armies can stand toe to toe with WoC in terms of combat ability (Dwarf characters, Elven elite units, Nurgle Daemons, HPA, etc)
Leadership - mediocre at best
Chaff - mediocre at best. What I would give to have some Chaos skinks!!! WoC fast cavalry pale in comparison to their Elven counterparts. Warhounds are decent, but nowhere near the level of a skink. No access to cheap flying chaff or scouts.
So WoC are far from invincible and I don't even think they are the top performing army in terms of top level tournament results. However they are admittedly very good, top tier without a doubt. I do think they can be a more forgiving army since they can often fight their way out of less than ideal situations, but I do not agree with people that claim that they require little skill to master. If your opponent is skilled, a WoC player has to be skilled to counteract them. If both generals are unskilled and just push their models straight forward for combat... then WoC will dominate.