I think all this talk about improvements benefiting lights more is wrong. In fact in think it is just the opposite.
Run a simple test 5000 heavy cav versus 100K at 0 attack armor and the 5000 heavy cav versus 1 million at say 18 attack and armor you'll know the difference.
In fact after a certain level of attack you wont be able to kill these 5000 heavy cavs no matter how many light spears you use. Evem with 10 million you'll lose.
The results will be more drastic if you use paladins.
Light units are crap and dont stand a chance against elites or heavy. Only light spears are awesome units because they are incredibly cheap they will swell your infantry flank your cavalry and give extra honor. And they can carry more load. Thats all!
What do you mean 10 million light spears can't beat 5,000 heavy cav??? Just 10,000 light spears are enough to thrash 5,000 heavy cav. And that's on the plains where cav get an advantage. Try it out in mountains and you'll find that with 10,000 light spears against 5,000 HC you'll win with almost 8,000 spears remaining. The question posed earlier in this thread is whether 6,000 heavy spears would be better than 10,000 light spears in the same scenario. I just tried them out against the same number of cav in the calculator and they were roughly the same, but the lights fared slightly better with zero bonuses. Adding +15 melee attack and armour to both sides, the lights still came out better, though not by a bigger margin. Interestingly the number of HC remaining was the same in all four scenarios. I'm not going to run hundreds of tests in the calculator to work out the exact difference, and obviously there are lots of different battle situations, but in this simple spears vs. cav example, light spears worked out slightly stronger than heavy spears compared with their cost to build.