I'm aware.
I'm not sure if TPS has ever attracted a senior officer (Inspector and up) from another service, and probably damned few Sgts. or S/Sgts. Lateral entry in police services is not particularly common, especially above the Cst. level anyway.
In an organization as large as the TPS, they shouldn't really have to 'go outside'. One aspect of leadership is to identify and groom (probably a bad term these days) your replacement, and TPS should be large enough to have sufficient bench depth. Smaller services do not, particularly when your get up near the peak. There is an argument; however, for a 'clean broom' - someone from outside the organizational culture.
The OPP and RCMP are a bit different. They're government appointments and the people doing the hiring aren't the equivalent of a Police Services Board. They aren't directly the employer and won't be dealing with their selection on a regular basis. There's politics in all of it and I'm not suggesting that there is political interference in police operations but certainly political influence in senior staff selections.
I said in the last post that, at the Chief level, operational leadership should be 0% of the job, but that is not totally true in smaller organizations.