In most competitive armies today Redundancy is a key to overall strength and is represented on three levels. The first of these is Redundancy Within Unit with the most common forms being a doubling or tripling of melta-weapons or multiple Missile Launchers within a single unit. These multiple weapons of the same type (including multiple special close combat weapons) ensure that the damage output of the unit is maximal.
The second level of the Redundancy Hierarchy is very common these days - Redundancy Of Unit. Why take one five man assault squad with meltagun and inferno pistol (2xmelta weapons thus redundancy within unit) mounted in a Rhino when you can take three or four or more of such unit? This redundancy of unit ensures that if one or more units of the same type are destroyed then there will still be more units to fulfill that role within the army. Oft times redundancy of unit is seen in MSU (Multiple Small units) based armies and is also related to (but not the same as) saturation of targets/units.
The third and final level of Redundancy is the often overlooked Redundancy of Role Across the Force Organisation Chart. This redundancy utilises differing unit choices and composition within the same category or across categories of the Force Organisation Chart. This is an interesting level as many competitive lists make use of this type of redundancy but the thought process isn't that of 'lets include a different sort of unit in our force from this unit here,' but rather more commonly 'I have no more Elites spots to fit more of this type of anti-armour in so lets take some anti-armour from my heavy support section.' The differences between these two are almost identical yet to my mind the latter is the inferior of the two.
At this point I've lost people, so lets expand. the latter thought process for list design could see a Tyranid player having maxed out on two units of Hive Guard and one of Zoanthropes moving to the Heavy Support section to include a Rupture Cannon toting Tyrannofex, and because they are crafty the fast Attack section for a harpy with Twin-linked Heavy Venom Cannon. All three levels of redundancy are here with redundancy Within Unit (three Hive Guard, three Zoanthropes), redundancy Of Unit (two units of Hive guard) and Redundancy Across the Force Organisation Chart (Hive Guard, Zoanthropes, Harpy, Tyrannofex) represented. the Tyranid player is well on their way to a competitive army.
The former thought pattern is different only because it will sometimes deliberately skip the second level of redundancy (Redundancy of Unit) to work in similar yet different options across the force organisation chart to achieve the same thing. An example would be Space Wolves. I could do what upwards of ninety percent of all Space Wolf armies do and take three units of Long Fangs armed with Missile launchers with a number of Las/Plas Razorbacks to add to the anti-armour capabilities of the army. But I'm not. Instead I'll take one unit of Long Fangs with Missile Launchers, a unit of ten Wolf Guard with two Cyclone Missile Launcher Terminators, a unit of five Grey Hunters with Plasmagun, a land Speeder Typhoon (Typhoon Missile launcher) and a Las/Plas razorback for the Wolf Guard and Grey Hunters. Points differences aside (we're looking at the theory not confusing relative points costings - it's an example okay), the second list selection presents Missile Launcher options in the Elites, Troops (Cyclone Missile Launcher Wolf Guard attaches to the Grey Hunters), Fast Attack and Heavy Support Categories. There's Las/Plas options across the force organisation chart as well. What this has done is freed up two Heavy Support choices allowing for more flexibility of choices.
A good chunk of you are turning away at this point disgusted by the recurring thought that the two thought processes on redundancy of choice across the force organisation chart are exactly the same thing. But they aren't.
The difference is saturation.
A Tin of Pears verse a Tin of Fruit Salad.
A tin of pears is all the same, there may be bigger or smaller pears but it's essentially the same flavour to eat.
A tin of fruit salad is many flavours, you are presented with choices - what do you eat first? If you eat all the tasty cherries first and end up disliking the taste of the remaining fruit you can't go back and eat the cherries last as they are gone.
This analogy is apt as it emphasises the differences. on the one hand, you build in redundancy across the force organisation chart because you ran out of ideal preferred choices elsewhere, whilst on the other hand, you deliberately build in redundancy across the force organisation chart even if at times you don't fully maximise an ideal preferred choice elsewhere. This latter approach builds a stronger level of saturation of units/targets into your army as it is no longer as black and white to prioritise targetting against you.
Both approaches are strong. Both approaches will give you a competitive army. On occasion though, the fruit salad approach of redundancy across the force organisation chart will completely throw a good player off their game allowing you to capitalise on their confused approach to dismantling your army to achieve a stronger victory then you otherwise would have.
