it doesnt do anything if you go down to 50% though

your initial point is that the first mover gains an advantage because the second mover does less damage in return

but for the second person to do less damage they have to be knocked down "enough" which is to 16% of the first persons buildings

or about 27% under the absolute most favourable conditions so somewhere between 27% and 16% it begins to kick in

(you actually have to go much further before it has a big effect because otherwise you hit max damage in a few hits anyway)

at 50% it does nothing new

edit:
also you dont kill 150 each hit, youd be killing 79 on the first hit mono 0 tech or 133 tyranny max tech, and it drops each subsequent hit

so at max in 16 hits you kill 1750, thats no where close to the 3650 you need to kill to start having an effect if they are tyranny max mil strat, i dont know why i said 25 hits up above but its actually 50 before you get them under 1330 which is how low they need to be before they start being crippled

sure a tyranny can do 50 ab's but that seems like a reasonable investment to actually start getting a returns

it takes an extra 25 hits to reduce initial retaliation by half when they are at 665 buildings left
so then the equal country comes along and does 75 ab's back for the first 50 hits it does only 66 damage, but after 75 abs the total buildings left is 960, vs 665, and thats assuming you never rebuild at all

worst case it would take you 23 extra hits to knock them down as far as you

nevermind the 4 on 1 scenario your using would be 200+ hits so express only