Are War Wagons economical to simply throw at the enemy in the long run?

I started playing Germany recently.

I notice that in long drawn out games, when I pour out only war wagons (fully upgraded), I have a very high kill to death ratio. Its always more than 2-1; often close to 3-1.

So when you have a strong eco to support, is it cost effective in the long run to simple pour out war wagons if you're too busy to micro every battle?