Armor messes up everything. There are heroes who have always been meta like Reinhardt and D.Va, negative changes to armor will help balance them. However there are also heroes like Orisa and Torb who are already pretty bad and further changes to armor will nerf them for no reason. Hence why I’d rather remove it and balance them separately.
Its simple you get stunned more then once then next effect should be halved the 3e effect even more after that you should be immune next 30 seconds.