About phalanxes vs warriors: one takes more shields than the other, and you might want the cheaper one. This is useful in Monarchy, for instance. On your borders you might want strong phalanxes to defend against attack, while deep in your civ, where there are few threats, you only need troops for martial law. In this case, you want to build warriors because you need three per city for unhappiness, and it's a waste of shields to build a bunch of phalanxes or archers when you don't need the good defense. Warriors are also very useful because you can build Leo's and a crapload of warriors, and then study Gunpowder. Then you've got a whole lot of Musketeers that only cost you ten shields each. I've said these things in another thread or two, and the point is, warriors are great units.
