Gannon has also been called a 'tactical maverick' due to his unusual formations. These formations include 3–4–1–2, 4–3–2–1, 4–1–2–3, and his preferred set-up of 4–2–3–1. He has stated that he prefers formations that use four lines of players (as opposed to three lines in the classic 4–4–2) due to the added depth in defence and presence in midfield, and was inspired to use the formations by Carlo Ancelotti. He has also stated that he prefers the 4–3–3 formation to the 4–4–2 formation, and has criticised the way he perceives 4–4–2 to be 'ingrained in the culture' of English football. He is known to be extremely thorough and meticulous in preparing his players for games.