I also had a bug with the attack system. for me it was an out going attack (to inactive player)
I've send a total of 2000 units but with the attack the counter of my units who died was 2299, which means my own team had 229 more dead then sended.
I had an attack modifier of 55% and he had a defence modifier of 200% and the attack luck was 3%.
I sended 1500 axe, 100 light, 100 mounted, 250 rams and 50 catapults.
on my side died: 1500 axe, 100 light, 100 mounted, 499 rams and 100 catapults.
he had 943 axe, 841 archer, 187 light, 105 mounted, 30 berserker, 10 trebuchet and a noble.
on his side died: 660 axe, 589 archer, 131 light, 73 mounted, 21 berseker, 7 trebuchet and his noble.
the wall wat reducted from 20 to 17 by the rams, the catapults were also focused on the wall but had no effect.
i think its best to lock down attacks while this bug is there. this can be real harmfull to the game if its get well known before its fixed.