Is it a better strategy to prioritize attention/resources spent on high performing employees or low performing employees? Why?

Both as they impact organisations in different ways. Low performers will negatively impact the business and impact high performers who may be picking up slack or causing higher workload - the issue needs to be addressed as quickly as possible.

At the same time engaging and nurturing high performers is integral to business success so investment should be made by giving them opportunities for growth via training, recognition, promotion, stretch goals etc.

You need to know what is happening with your low performers, they might be in the wrong role, don't have the right leader or are restricted in resources. A lower performer has to be supported before writing them off, you might lose a good person while the root cause is not solved...

I believe you have to focus on hiring the right people and managing those who want to be there. It is also important to identify your low performing employees and equip managers to address concerns and hold them accountable for quality work. The primary focus should be on those who want to be there and a demonstrating a drive to produce high-quality results.

We definitely spend more time on the higher performing employees to ensure that we're keeping them engaged, and that they have developmental and growth opportunities. While we do try to address our lower performers, our efforts and time are much more spent on higher performers and making sure that we're developing and growing that population.