I often discuss unit efficacy with my 40k friends. We choose a unit, and try to come up with the most optimal way to kit it out for a plethora of hypothetical situations.
This is a great way of coming up with a good loadout or role for a unit that can operate effectively while isolated and/or unsupported on the battlefield. For example Terminators, Land Speeders, Falcons, Hammerheads, Tau Battlesuits, Daemon Princes, and so on. However, when it comes to selecting an entire army, a collection of individually excellent units can be a mixed blessing. Even if these units are great at what they do, the synergy of the army may be hurt in the process.
A great example of this line of thought is the meltagun. It is widely renowned as the most cost-effective anti-tank weapon in the game. Taking all meltaguns must be the way to go, then? No. The meltagun is only effective if you can get it into range of enemy armour. If you don't have a single lascannon in your army, you're giving the enemy the freedom to move his vehicles outside the range of your meltas. Letting the enemy move freely around the board is a sure-fire way to lose the game in Warhammer 40k.
Another example is the guys in the picture up top. Thousand Sons are a peculiar bunch, and I've often seen tacticas on the web, telling everyone that the Doombolt is the only power one should give the Aspiring Champion. However, even if the power neatly matches the rest of the unit's shooting, one of the things I often lack in my Chaos armies are mid-range anti-tank. Something that fits neatly between the Lascannons on my Land Raider and the meltaguns on my Chaos Marines, is the awesome power of the Bolt of Change. Even though the unit of Thousand Sons themselves benefit more from the Doombolt, the army as a whole will benefit more from the Bolt of Change.
To emphasise my point; even if the Land Speeder with Multi-Melta is the greatest thing since Rending was on to-hit, if your army has enough mobile anti-tank, you should consider the Typhoon instead. Even if it is less cost-effective on its own, your army may benefit way more from an "inferior unit" than the optimized build.
What do you guys think? Are you always checking the internet for the latest optimized build of single units, or are you experimenting with which combinations of units works and which doesn't?
