They didn't lower any features of Polearms and Two handeds, they are just fine the way they are.

Problem is, they improved "Cavalry Charge" ability so high. They probably thought that cavalry charge was ruling the medieval ages. That's true. But now, even the lightest cavalry with jousting ability crushes the bestest polearm infantry or swordsmen, only by charging. Hell, they crush most of the spearmen too. Since no one have pikemen in early and mid game, there is no solution against mass cavalry charge.

(That was not the case in Rome TW. Most of the factions have pikemen, and even they dont, high quality infantry resists the light cavalry charge perfectly.)

But in the normal engagement, two handeds and polearms thorn the cavalry to pieces just like in the old days. Problem is, if more than half of the unit is dead after the first charge, they most likely can't do anything, or rout.