Doesn't matter if he unites them or not, his cause is doomed. The United States can produce pistols, swords, rifles, cannon, lake and river gunboats, supply wagons (and oxen to haul them), and gunpowder. The native American confederation would be unable to produce any of these things. Its sole supply would be from the British, which would dry up once the War of 1812 is over. Furthermore, U.S. forces, including militia, had become battle hardened and by 1814 were racking up impressive victories against professional British soldiers led by professional British officers. If the U.S. could defeat these forces it could defeat Tecumseh's confederation with ease. As to leadership, good commanders had emerged on the U.S. side of the War of 1812, such as Andrew Jackson, Winfield Scott, Jacob Brown, Thomas MacDonough (Battle of Lake Champlain), Oliver Hazard Perry (Battle of Lake Erie) and Alexander Macomb. In addition, the U.S. had a sizeable number of West Point graduates trained in at least the rudiments of professional tactics and of military engineering. For instance, West Pointer Macomb employed his engineering skills brilliantly as land commander at the Battle of Lake Champlain where his troops gradually fell back into prepared positions designed to confuse, split, channel, ambush and defeat a British army that outnumbered them ten to one (the British withdrew). As a result of the war, West Point was expanded and its courses systematized, which would have given even more of an advantage over Tecumseh even if the final showdown with him were delayed by a few years. My personal opinion is that any major victories by Tecumseh's federation would be reversed within months, not years, and the idea of Tecumseh blocking U.S. expansion into the west by an entire generation is without merit.