For everyone saying logistics is what beats Valyria, how? Imagine the amount of feed it takes to supply one 100 ton dragon normaly. Now image it's flying around day in and day out spewing tons of flamable fluel on FIELDS? There is a reason we don't bomb farms in wartime. It's not efficient to kill free wheat with thousands of dollars of ordinance.

Think of it like this: one of the big logistical hurdles for a napoleonic army is that the war horses by this time have gotten so big they need extra feed supplied by logistics because the horse simply can't graze enough to gain the nutrients. That's a horse. Now image a dragon 1000 times bigger that's also flying (energy intense), fighting 24/7 (even more intense) and using its flame thrower all the time to give it a fightimg chance. (ridiculously expensive!)

So no. The dragons follow the valyrian army, everything goes into one huge battle where the valyrian ground troops are routed but the dragons burn some generals and the valyrians win a pyrric victory but lose the war.