Heh... they won't give you that much money to train paladins, especially not 20 at a time. But in general, you'll have to use them to fight Ents instead of Dryads))) We'll have to see.
And if you recruit 20-30 extra paladins (in addition to the ones you train), they will be more useful in battle than all your Dryads, even with their super-spell - summoning an ash swarm, which everyone here loves to praise and which is actually "0" benefit.