Strategist Dalek (New Dalek Paradigm)

The Strategist Dalek was one of the new species of Dalek that emerged from the Progenitor in 1941. The first Strategist Dalek destroyed an "Ironside" Dalek and the leader gold Dalek. It worked most of the machinery inside the Dalek ship and escaped through the time corridor with the Supreme Dalek, Eternal Dalek, Drone Dalek and Scientist Dalek. (DW: Victory of the Daleks)

Behind the scenes
According to Doctor Who Confidential, the name "Strategist Dalek" was coined by Mark Gatiss as one of the new styles of Daleks. Gatiss also coined the names of the White Supreme, Drone and Scientist Daleks.

It could be said that the Strategist Dalek is second in command of the five Daleks.