Speaking as someone who has fought a dragon that was level 44.....they are not by any means WEAK.
Their fire does lingering damage which can be a massive problem for infantry as the dragon if properly used can spread fire and then fly off leaving your men to burn while it skitters off.
Really if you let a dragon get pinned down (or in one terrible case for me my Royal just STOPPED obeying orders and stood there to get butchered) it's your own fault that it gets slaughtered.
Dragons take a bit of skill to use I'm seeing, I've fought so far only a handful of PvPs where the enemy had dragons and it didn't glitch out on me. A few were easily destroyed because they just sat there and ate the damage.
But I also lost several matches because the dragons kept on moving and leaving my poor guys to slowly cook in their own juices lol