I tried to reduce the unit size for elephants, it didn't work. The game wouldn't load with fewer. I didn't experiment a lot with that so perhaps there are magic numbers that make it work, or some switches that need to be checked.

There are a number of issues and no single one (or two) fixes things. The lack of crew kills is a real problem, esp with the archer carrying types. Armour is too high (should be more defensive skill) and hit points are too high.

Tonight I ran into a Carthaginian army with a single set of war elephants. It was a nicely balanced army, but I had a better, well balanced Scipii army. It was on "hard" not "very hard." With the war elephants it was a disaster--even with my modded cut down elephant stats. Without the elephants it would have been a straightforward win. I had fought many similar without war elephants in the same campaign, and I had even destroyed an a couple of elephant units earlier when I had a higher ratio of troops. The AI army mobbed in with the elephants and routed half my army in a few seconds. I hit them with Balearics as they came in, then attacked with two units of velites followed by samnite mercs and principes (all of these were heavily upgraded), and a unit of legionary cav when it routed the enemy cav on that flank. I managed to kill about a third of the pachys by using 1/3rd of my army just for them...

The base level elephant mods look about right--very dangerous but vulnerable, but the other two are a bit too hardy. I'll have to knock a few points off their defense. I want them to be tougher than the forest elephants...but this is still too much.