He has a reductionist approach to problem-solving.

He is a reductionist.

The reductionists believe that all complex phenomena can be explained by reducing them to simpler components.

The reductionistic approach to understanding the human mind oversimplifies its complexity.

Reductionisms can oversimplify complex phenomena.

He approached the problem reductionistically.

She approached the problem reductionally, breaking it down into smaller parts.