I'm against stacking. If you want to encourage midfeeding and stuff you have to allow people to attack with a balanced military and get good amount of land while being able to maintain a solid defense against special attacks and having a chance of making a retal bounce.

The more likely retals are successful on similar size countries, the less incentive there is to take the risk of attacking a similar sized country. If you can get 4000 acres and bounce an attack 40% of the time, that is more productive IMO then getting 4000 acres with a 95% chance that the other country will take back 2700 acres.

The more the bonuses stack, the less a country is capable of defending themselves (unless they attack a much smaller country). This had the end effect of attacking the smallest country you can being the safest and most efficient way to grow in land.

Making retals bounce for even size countries IMO has the effect of encouraging risk taking, so that's why I'd be against stacking.

I'd much rather have a military strength bonus for more turns but less powerful. A 5% bonus over more turns is better. There are enough disadvantages on the defensive side already (planned strike +50%, 2 vs 3 def to off ally imit). The first country declaring war having a 10% bonus.