Usually people settle GGs or make super units, but there's another useful option (tho not all the time) I didn't see much mentioning. When playing CHA leader, you only need 8xp to get to CR3. A barrack gives you 3xp, a GG can provide 20xp, which can be evenly distributed to 4 units, or 5xp each. Say you've been playing a CE peaceful early game, and have a dedicated unit city pumping out melee units, at 3xp each, so you have a whole lot of these 3xp units standing around. When you get riflemen or grenadiers, and started attacking and getting some GGs, each GG can make 4 CR3 riflemen or grenadiers. Or infantries. Of course, this is probably only useful in this specific scenario (CHA leader, with lots of 3xp melee units around), but it's good to keep this in mind. In my current game, I am playing as Brennus (CHA/SPI), one early war, so I have a few CR3 units already. I kept pumping out maces every 2-3 turns all game, so when rifles arrived, I started war with some whipped 3xp riflemen, use them to take down a weaker AI and got some GGs. Then I put 3 3xp maces and 1 high-xp CR3 axe in the same square, and attach a GG to the axe. This way, the axe gets upgrade for free, and doesn't lose the high-xp when upgraded, and the 3xp maces are turned into CR3 riflesmen.