Matsuri is based on level, so if you have a poor power-to-level ratio even for a free player, Matsuri will more than likely be a bad time for you. You also want to have at least 3 teams with no overlap or very little overlap if you can help it, so that losing and resetting to fighting weaker opponents is no big deal.
Matsuri is based on power, not level. My level freezer in UK (lvl 82) basically only face 90 - 95s in matsuri. In the unlikely event that I actually lose a fight, the next opponent is almost certainly going to be a 90+ player of lower power.