I met only a few good engineers in my career. And hunted are also mediocre and poor ones. However, hunters look for suitable ones. Their stereotypes prevent them from finding.

Job switch is always uncertain. I do not see any reason for the red flag for somebody. People drive their lives, and having a 2, 9, or 24 months break is a legitimate decision. There are now around me highly qualified and experienced people. Multilingual, with many complex, difficult, and successfully delivered projects under their belt. And they can't find a job. Their only sin is age 45+. This is an example of what I try to address. Not java developers, mostly PMs, but still technical people.

My experience is that organizations prefer building knowledge for years instead of hiring one or two persons who already have the expertise and help deliver change in weeks. This makes me think that time does not matter. I may be wrong. What matters is having a good system, that help organization to create human capital - hiring, training, autonomy, space to apply knowledge, space for controlled risk. It is very rare to see something like this.