Agility player - for example 18/24, don't have any penalties for heavy armor (for example using transitional armor)
Strength player - for example 24/18 - same transitional armor.
With this builds above - STR player is slower, and they both will do about the same damage (because of speed bonus and more wpf for agy player), and AGY player will spam STR player with more fast attacks.
So what is the advantage for STR player?
If devs raise difficulty for all armors and weapons, than will be more balanced.
If player want to use heavy armor and heavy weapon he will need to invest in STR. If someone want to play with more AGY he will use light armors and weapons.
And that is common sense and more balanced game. That formula is used in so many games - more STR - heavy class / low str - light class (more AGY).
Right now AGY have huge advantage.