Negative. The in-game lore and story says that dragons enslaved the world with their power, and were killing people by the hundreds, even thousands. Nobody stood any chance against them until people learned to shout. Common animals, and regular guardsmen have no business slaying dragons, and our dragonborn character should only be able to kill them with great effort.
And that's true for Ancients...and for Elders to some extent.
I've made some tests on the pc version, spawning the various types of dragons in giant camps and cities, on master difficulty.
The only city able to withstand an Ancient Dragon attack without too many casualties was Solitude, because there are near 20 guards...add another Ancient and guards start to die like flies...
One Ancient is enough to kill every guard and every killable npc in Whiterun/Riften...smaller settlements like Riverwood, Rorikstead or Dragon bridge just don't stand a chance...
As for giant camps...a Frost Dragon can emerge victorious, but badly wounded and crippled to the ground...Elders and Ancients wipe the camps.
So, the dragon race IS powerful enought to take over cities and to enslave the survivors even in game. The only problem is that basic dragons are too big and impressive so when you meet them you EXPECT them to be powerful...but they're the weakest of their race.