Hello Sean, Hope this sheds some light on your loss, Plarium cant calculate anyone else except your own personal stats because there is to much to calculate when you add how many boosters there are in these battles. Without getting to into it, All red numbers in your battle reports against other players are with no boosters and level 1 in lost arts (the base stats). That player you burned was level 71 so id say generally they have a devolved castle with decent boosters meaning you are typically good to take that red number and x2 it. So in reality he probably lost about 1.4mil troops to your 1.7mil troops.

Defenders typically get the better ratio as well when a castle has a good permanent defense (10,000 walls gives a 100% boost to all troops at that players castle including reins they receive so anything above that is amazing for defenders) as well as in this screen you can see he has a well rounded troop balance defending his castle with a decent amount of each type (infantry, Calvary, occult, beast).

What Ive been told by many players (and even done tests myself with friends of all different levels) is you want to take red numbers anywhere from x1.3 to x2.5. This all just depends on your enemies castle development.

Please if you have any more questions about this just comment below and ill try my best. I only went into a general topic about this as its a bit of explaining for the full thing haha :D