its all about the choices you make. make wise choices in game, and you shall succeed.
Here is my team when I beat Red is GSC. Of course, his team was at a lower level than it is now, but still pretty high up there.
Lv 65 Typhlosion
Lv 62 Suicine
Lv 64 Lugia
Lv 60 Eevee
Lv 67 Entei
Lv 66 Raikou
And I beat him. Of course, it took about 20 Max Potions, and 40 Revives, but I beat him. His team were at lower levels, though.
You really rushed through the game, lol.
I've had it for nearly 2 weeks now, and I'm just finishing up Kanto. I prefer to play at a slower pace.