I doubt it, often headcount back-fill puts in a more junior person. So post poaching, you might see the company hire a replacement outside engineer at lower salary than the person he replaced.

Also, again, this is only about no-cold-calling. If someone truly thought they were hot stuff, and wanted to cash in, all they need do is threaten to quit, seek out an offer themselves, and they could gain your "fairer" distribution.

In fact, it was not at all uncommon to people to threaten to leave and get big counter-offers to stay in recent years, especially higher level employees.