A good consultant would answer that everything depends on the level of an organization, services offered, and business objectives.
One thing is for sure: whether you need to assemble a new team, supplement current projects with more talents, or replace current ones, you will do everything to avoid frequent voluntary turnover. It negatively impacts productivity, team spirit, and an organization's revenue.
When you need to fill in a job, it is natural to review both trainees and the best candidates on the market. Either way, things may go right. Let's see what you can gain and lose when you opt for hiring or employee training methods.