If they were released at the same time, there's absolutely no way to know which games would be more competitive. They're more likely to be an even split due to their exact differences and characters. It's honestly irrelevant.
Brawl does not have everything Melee has or vice versa. Melee doesn't have footstool jumps, super insane courses, MK, the same characters, tripping(only bad one), the same moves or a playable dragon(like) character who can fly either.
No, they are not the same or similar. And exciting is completely subjective. I actually thought Brawl had a lot more exciting aspects. Combos, I agree, but that's what we got infinites for. Speed? Brawl isn't really that slow as you're making it. I like campy gameplay myself. Why? It's an interesting defense play. I do wish it was a bit more offensive, but honestly, still doesn't bother me.
BTW, I like Melee more, how about that?