>>32360705Actually, because of how gen 5 is made I don't believe it has as much as gen 3. Audino grinding is grinding wild Pokemon which I don't take into account. In addition, you shouldn't need to grind wild Pokemon to begin with in a game with a well-balanced level curve (and this is true in gen 5).
Furthermore a lot of those trainers you mentioned who are around level 30 (and this is true, they're around 25-35) are optional. Many of them are available when you get Surf which is why they do that. However, because of this your team is able to stay at around the level of the gym leaders which is why I like it and say it's a good level curve. The trainers outside of that tend to stay above that level 30 range since they're more on the storypath.
That's my reasoning at least.