I agree. Kongo now has a real disadvantage during the era of their UU. Moving quickly through forest and jungle is a nice gimmick but it no way is it worth a malus of -5 strength which pretty much guarantees a loss against a normal swordsman. The advantage for the Legion is now just being resource free and the ability to repair tiles/build forts, not very impressive at all considering it conquered most of the known world of its time.
The change to swordsmen must be especially egregious to the woeful Berserker, who previously was a little weaker versus a much cheaper and earlier unit but is now roflstomped by them
If they wanted to curb the power of UUs they should have started with the Scythian horsemen zerg, two for the price of one is still the most powerful unit ability there is and when combined with their 50% heal on kill its just silly.