Culture is important and you cannot put it at risk by hiring misfits. It is not good for you as an org and not good for them as employees. However, we do tend to become rigid. In the garb of culture fit, mirroring works and we are often looking at creating clones.
I would invite you to think about focussing on 'culture adds' when you hire so that you:
attract and maintain diverse talent pools,
foster creativity and innovation by bringing in divergent thinking, idea
its good for your business, you create better products, services
Culture add is about looking for those who will help you grow what is already present, working...they don't just fit, they add to what is existing.