EDIT: Disregard the following, I forgot my units don't have splash damage. It just took a little while for my brain to work it over. Everything is well in the world again, feel free to remove the thread as unnecessary.
I just tried to fight the 180 dogs and 20 rangers camp in sector 8 using 104 recruits. Maths based on tooltips states that there's an excellent chance of winning the fight in 1 round and the fight is a guaranteed win in any case. To my surprise I lost and only managed to kill just over half of the dogs. Here's the fight progression:
Dogs first strike, killing 37 recruits, this is normal. Recruits+general attack, killing only 68 dogs. The tooltip states the dogs have only 5 health, and the combat replay agrees showing the stack to have 900 hp. The remaining 67 recruits and the general do just under 1200 damage at the very least, so something is seriously wrong here. The expected damage is around the 1800-1900 mark, so the dogs would seem to have 5 times as many hitpoints as the tooltip suggests or there's some other hidden mechanic out there that's not made apparent.
The next round after first strikes there were 32 recruits and the general left, and they managed to take only 33 dogs out. Same thing here, around one fifth of the expected number.