Having a probationary period is always good, and resetting expectations at 6 months is good to. The way Google used to do this was you were hired but you weren't actually set in your job/grade (slotted). After 6 months to a year they compared you to your peers and figured out if you were correctly placed. Generally if it was "close enough" you could move on, if not, they got rid of you.

The sad thing is that it isn't necessarily the candidates fault if aren't cutting it, some managers were MUCH better at onboarding than others. So good people were lost, some not so good people retained.

As for 10% a year pay hikes, that just doesn't work. You'll double their salary in 7 years and double it again in another 7, so with 14 years experience you think they will be 4x productive as someone new? I could see it being great for retention (problem solved!) but hard to build a business model around it.

I was thinking of proposing something like the "assistant" idea, so good to have confirmation I'm not the only crazy one.