Here is how the actual battles went with you being the first column and your opponent the second column:
Slot 1: 510 vs 1
Slot 2: 510 vs 1
Slot 3: 255 vs 208
Slot 4: 0 vs 420
Slot 5: 0 vs 420
You win slot 1 battle, 1 kill, no losses.
You win slot 2 battle, 1 kill, no losses.
You win slot 3 battle, 140 kills, 85 lost.
Fight seems to be going in your favor, huh? Here is the problem. There is no one to fight against your opponents 4th and 5th slot. So they get free hits on your 3 slots.
You lose slot 4 battle, 0 kills, 210 lost from 1st slot.
You lose slot 5 battle, 0 kills, 210 lost from 2nd slot.
End of round 1, you have lost 505 soldiers and your opponent has lost only 142. It is now your 770 vs their 908 soldiers. You both now have soldiers spread out in 3 slots and the fight is more even now, but sadly you having less soldiers will end up losing a battle you should have won.