The game is about Sengoku Jidai. That's roughly mid/late 15th- early 17th century. Quite a lot changed in samurai warfare during that time. The large units of ashigaru with huge pikes became dominant during the later stages, mounted archers were still of use during the early stages. I certainly hope that TWS2 will give us enough time to enjoy both the early, mid and late era (maybe even a switch to turn events of and stay stuck in early or mid). What do we know about turns, will they be months?

I've played some pike and musket like games in totalwar, both in single- and multiplayer. They are different, but certainly not bad for me.