Holeypaladin
Or you could be more aggressive and keep attacking, rather than trying to hold an indefensible line that they can just fly over...
Starshine
You've gotta have back up against the dragons ^^ Front stack to push your territory further out and back stack to kill the dragon that jumps on you.
True, but if you put everything in one stack...
1. They might pin your main force with an attuner each turn making you unable to advance.
2. You need to guard at least 2 portals or flamewing might get 6/6 portals and win.
3. Letting them run unchecked behind your line means you are losing mana resources and portals, pathways for your newly summoned units to rejoin your main force, and if they try to pin you it'll be easier for them.