Pinner had been observing the situation for a while. When he first came across Kai and his group, he could tell they were strong Altereds, able to deal with what was thrown at them, and meaning the Zodiacs had to get involved.
Still, at least the Altered around them could be of some use to taking these guys down, making it easier for Pinner, Berry, and Lena.
However, when they caught up to them a second time, he could tell just at a glance they were stronger than he thought. Working together, they were receiving some type of boost, and even with the three Zodiacs joining in, it would be a tough battle.
So Pinner had made the executive choice at that moment to split all of them up. He used his powers to carefully place several of his explosive blue fur balls all around the highway. He had done so in such a way while they were in the middle of the fight that chaos would arise.