Before you select your team for blitz, sub in a character for another character that would put your team total less than 10% less. Then queue up for a battle. Before you select the team to fight and start the fight, go back to team select and swap in the original member of the team. When you go back to the choose an enemy screen the enemy teams are the same and are still based on your weaker team strength. This makes your fight easier to win, but also decreases the amount of points the fight is worth (good for initial climb or harder higher tier fights).