There's no doubt GF need to cater to the more experienced players in their games. I personally am hoping that BW and BW2 are just GameFreak testing the waters of more advanced story lines, and if that be the case due to the success I believe we will very soon get more challenging story lines and quests in future Pokemon games.
Back on-topic; I found myself having finding a type advantage before every gym in every game I've played, in Emerald for example I'd start with Treeko, catch a Wingull for second gym, get an Aron and Mudslap my way through third, I never struggled with Norman, Wingull again for Flannery, Aron dealt with Winona with ease, Tag team Tate and Liza with Treeko and Wingull, Treeko for Wallace and that's all 8.
Every gym leader in 3 Pokemon (Obviously I would have evolved at the first chance I got.)
There will always be something super-effective towards a gym before you face it.