Not necessarily. Power doesn't mean nothing. Power by itself may not score you a victory, but it and a combination of other factors including a good strategy will earn you wins. So technically, power isn't nothing, it does play a crucial role.
How so? According to your previous claim, you said as long as a team has a good strategy behind them, then they can beat substantially stronger opponents. So, then, why wouldn't a team of combee win against a tougher team, if they had a better strategy?
In response to the topic, no. I'm not much of a competitive battler, and when I am it's only against my sister, whom of which just liked to play for fun.