I'm not sure if it isn't too limiting to be discussing only infantry. The modern battlefield, and the advances made, are about combined arms, or at least combined arms principles. I would recommend Robert Leonhard's Art of Maneuver and offer his discussion of combined arms theory (complementary principle, dilemma principle and Alcyoneus principle) as a good theoretical lens for discussing tactics (the attached link provides a decent summary: http://www.operations.dns2go.com/ops...ned%20Arms.htm).
It seems to me that the history of infantry tactics through the 20th century has been to give smaller and smaller infantry units an organic combined arms capability (LMGs, suitcase ATGMs, marrying up with APCs, etc.). The new paradigm, call it distributed or whatever, is to increase those small units combined arms capabilities through greater reachback via networking to firepower and support (UAVs, JTAC training, blue force tracker, etc.). Additionally, the recent emphasis on COIN and Stabilization is about bringing more civil-military skills and tools down to the lower levels. The "strategic corporal" concept merits recognition here, along with Special Forces Unconventional Warfare theory. I would also add VADM McRaven's Spec Ops book as good theory for special operations as they apply to raids and direct action.