attack damage bug

I've been noticing since update 3.11.5 that when i attack an oasis or fort my troops do not do as much damage as before. today i sent 3902 archers at an oasis and they only killed 196 cav per wave. That's only 25.11 damage per archer or the cav have an hp boost that no one knows about. My archers should be killing 468 cav with just base 60 attack damage, if my basic math is correct. i also noticed when i was farming forts with cav only that i had to increase the numbers to minimize losses to where they should be. Is anyone else noticing this? Also im using the Galaxy S3.