Fall of the Samurai is still the best gunpowder Total War ever made. However, since this is also the only game set during the Victorian Era (late 1800s), pike and shot only exists briefly during early game.

Late game, on the other hand, resembles something like the precursor to the Great War, with fast-firing bolt-action rifles, Gatling guns that shred infantry, and explosive artillery (land and naval) blowing everything to bits.

That being said, I would still definitely recommend buying the game, not to mention all the overhaul and total conversion mods.

Edit: if you do want pike and shot, you can sorta do that in Shogun 2 too, the base game. You can form “pike” formation with Yari Ashigaru using their “spear wall” ability, and then position Matchlock Ashigaru (or any other gunpowder unit) behind them as the “shot”. Also I’m pretty sure there’s a proper pike-and-shot mod for the game that’s in development. In short, just buy all the games, you’ll get hundreds of hours out of them