I am pretty sure the only thing that is not given to us as players are the decimal points they add to everything. it is not a deception, it is just not given.
plus 75% revival and 50% free revival are two totally different things.
75% revive are units that are in your infirmary already.
50% revive is what Is considered after the original battle math. and that just means you will be able to revive 50% offense or 30% def after attack. in each battle you instantly lose a certain amount of units that don't show up in infirmary. it think if you use 12500 agemas only 10k or so will be available to buy back. so what you are missing on your math is the total number of units that completely die off in battle. + with the number of lets say offense units that die in your city/ what shows up infirmary. that will give you the number of free revival.
but really you should not leave offense outside, then this conversation would be about the 30% revival on def. and then the math is even better. if you don't have the exact number divisible by something close to 3.798 then you will never see the 30% units after attack( total number of units - number that completely dies off=x. x/3/4 infirmary and x/1/4 free revive and it is something like that. but that is not even close to being right because it is based off of 1/3 not 1/4.
this is where I think it is decimal points that they are not giving. I could be all wrong here would like to see what anyone else has to say!!!
#PLARIUM MATH IS THE BEST.