Yes, the servers are down right now, they have been down for about 6-7 hours for everyone, I guess it will be up again very soon, hours or so. (just my guess)
The attacking order depends on the speed of the cards, and the speed buffs / debuffs some cards give to your whole army. normal attacks always hit the enemy card that is in front of you, sneak attacks attacks the card that is furthest away, snipe attacks closer enemies in the backrow.
Ahh, that's interesting to know about the attacking order and which cards get attacked. I'm new to the game and had no idea about this, will definitely have to do some research into the mechanics.
Hopefully the servers are back up soon :)