The AF system is a bit simpler. At least in the CAF and RTUs, if you're an IP, you are qualified to teach everything from instruments to tactics, with the exeption of maybe NVGs, but that's generally part of the IP upgrade as well. If you're an EP (same as stav/eval) you can give a checkride for instruments or mission tasks to anyone, IP or regular line pilot. from what I remember EPs have to get evaluations from squadron Stan/Eval guy or above (DO or CC or group level Stan/Eval). Commanders (always EPs) get their checkrides from group stan/eval (usually the OG/CC) essentially insuring that there is no command or supervisor influence on the evaluator. There are some local restrictions on who can give checkrides to who, but that's above and beyond what'd dictated in the reg.