I mean, that's a general philosophy: it doesn't place any limits on the actual level power. 

Airbending could go from just using gusts of wind to shove your opponent around, to hurricane projectile sheilds, air sledgehammers and even rune-traps that release shockwaves upon activation. Waterbending could only allow one to draw water to their hands from a source and then shoot it out in form of a high-pressure jet; or it could allow full control over water in a certain radius, allowing to attack from virtually any angle in close quarters, and also include temperature manipulation to create ice barriers and scalding steam torrents. The actual physical amount of the element one can manipulate also makes a huge difference: being able to hold 10 and 100 litres of water at a time is a huge difference.

So yeah, even with a single element alone, there's a wide range to account for.