I'm currently playing with the Turks and I have yet suffer a defeat since I started recruiting Janissary Musketeers. I find that 3 rows works quite wonderfully at times. The first row fires, switches with the second and then with the third and reload. At the same time the former second row (now 1st) fire and switch with the second, and the third and reload etc. There are some oddities sometimes but nothing major. I have more problems with two rows than with three.

And the Monster Bombard. Wow. It's a bit over the top since you can do the same job with a few cannons, but when that thing fires everything that it hits goes down (it's very inaccurate against troops though).