Napoleonic is an obvious path and the engine could go toward the ACW, (infantry fought shoulder to shoulder and in line much more than one could imagine,the attackers always to be honest). But I'll see also a step back to cover the gap from the end of MTW2. You had a lot of very interesting war, with increasing development of weapons and tactics in land and sea warfare. From the pike and arquebuses of the Renaissance (Melegnano, Pavia) to the caracole and leather guns of Gustavus Adolphus (Breitenberg, Lutzen, Nordlingen) the siege masterworks of Duke of Alba or Spinola, the Grand Condè's Cavalry charge at Rocroi, the strategic laces of Turenne, Cromwell against Rupert, Drake and the Invincible Armada, Monck and De Ruyter, Iberville, Doria, Don Juan or Kheirredin.