Well, guys with ridiculous KO power and the skill to use it will dominate overlesser trained people. But for instance look at Chuck Liddell, he's a perfect example of 'styles make fights'...He dominates UFC, because no one can get him to the ground and his stand up game is just overpowerful. But compare him to, Pride FC fighters like Rampage Jackson, he completely dismantled Chuck...yet he can't manage to defeat Wanderlei Silva. Why is that?????? Chuck is all about hand strikes...Rampage is faster and stronger so its an easy fight...not to mention Rampage has tremendous ground and pound game. Why doesn't he match up against Wandy......because wandy not only attacks with powerful punches, he mixes muy thai into his arsenal, and as you could see in their second fight, Rampage cannot defend against wandy's knee strikes...STYLES MAKE FIGHTS...
Its good to be multi-balanced, having great ground game makes you superior when the fight gets in close but having the ability to end a fight in a split second saves you the time...I personally believe that Muy Thay, or Kickboxing, would be the best compliment to BJJ. It gives complete all around game and allows for more dexterity, and flexibility as far as options when it comes to fighting.
But in the end, honestly it comes down to technique, I've been in fights where I didn't have to throw a single punch because the other guy didn't know how to avoid what I was doing. Shoot for the tackle, wrap up the legs, take em' down. Before they know it they're on the ground and they're doing one of 2 things
1) trying to figure out how they got on the ground
2) wasting energy trying to get back to their feet so they can be in effective striking range
Either way, I'm calm and confident...I allow them to tire themselves landing weak punches to either my back or ribs...then I use my training to get them in an "unfavorable" position where they either get something broke or they beg for mercy. Whats better than that honestly???