Do you prefer armor or attack?

The "defense" and "offense" skills are roughly equal in priority; which one is better depends on the specific map and the situation. If you are playing as a Barbarian and plan to rush, then offense is preferable (especially combined with Craig's rapidly growing attack). However, if there are Dragon Utopia sites on the map that need to be taken as quickly as possible, then defense is simply a necessary skill. Taking Dragon Utopia sites with defense versus without it are two completely different things!

In Dragon Utopia and other structures, usually the "meat shield" takes the first hit—someone you don't mind losing and for whom defense isn't as important (especially if the unit count is 1)—and it is much more pleasant to deal 30% more damage with 1-2 striking stacks and completely wipe out the neutral stack without taking losses; just like with Barbarian and Viva creeps, nothing stops you from bringing a couple of small units into battle just to put them in harm's way

The longer the "meat shield" stands, the more intact your striking stacks will be. If you enter a Dragon Utopia on week 3 with Craig using parameters 17-3 without defense, it will be a fail or at least result in heavy losses, because the "meat shield" will be gone right after the gold dragons hit, and the green and red ones will start biting your striking stacks; after that, such high attack won't help, because there will be no one left to fight.