The issue of Keen and Improved Crit stacking can't be about the number of dice being rolled.
It's more about weapons with high crit ranges outshining other weapons when you add in bonuses or other ways to increase the threat range. The fact that critical hits multipy constants to damage increase the effectiveness of abilities that give the bonuses.
If 45% of the time I swing I get the chance to double my power attack, my divine might, my weapon specialization, my flaming burst and my smite damage and I were a powergamer I certainly would do it.
This also limits a designer's ability to come up with new ideas related to what can happen on a critical.
Anyway that's my take on this.
It's more about weapons with high crit ranges outshining other weapons when you add in bonuses or other ways to increase the threat range. The fact that critical hits multipy constants to damage increase the effectiveness of abilities that give the bonuses.
If 45% of the time I swing I get the chance to double my power attack, my divine might, my weapon specialization, my flaming burst and my smite damage and I were a powergamer I certainly would do it.
This also limits a designer's ability to come up with new ideas related to what can happen on a critical.
Anyway that's my take on this.