по ходу формации из декуриона, можно брать и без самого декуриона))) нот бэд
"If you are using the Unbound method, simply use the datasheets later in this section that correspond to the Necron models in your collection. If you are using the Battle-forged method, you will instead need to organise the Necron models in your collection into Detachments. This is a fun process in its own right. The most common of these are the Combined Arms and Allied detachments. Note that you can also include any of the formations presented in this section as part of a battle-forged army.
Furthermore, the Necron Decurion Deachment is a special type of detachment that can be included in any battle-forged army. Unlike the detachments shown in Warhammer 40,000: The Tules, it has a force organisation chart whose slots are combination of specific formations and army list entries instead of battlefield roles. However, it still has compulsory and optional elements, as well as restrictions and command benefits, just like any other detachment.
Although units cannot normally belong to more than one detachment, units from a formation that is part of a Necrn Decurion Detachment are an exception. They count as part of both their formation and the detachment, and have all associated command benefits and special rules. If your warlord is part of a formation or an army list entry that makes up part of a decurion detachment, that entire decurion detachment is your primary detachment."
Read more:
http://thetyranidhive.proboards.com/thread/48760/new-necrons-codex?ixzz3Q2ePg8NK=undefined&page=14#ixzz3Q33wV6e3