Every job is different, landing a pilatus on the Kluane glacier is of a standard a little higher than landing a C-150 in Brampton Ontario.
No, the standard is
different, not necessarily higher. At Brampton (where I learned in the '70's) they have a very high standard of expecting every pilot to land so as to remain on, and stop by the end of, the runway, and doing so is accomplished by following procedures presented for the plane. For all my ski flying, the procedures focus much more on technique, than achieving a landing in a defined lateral area, or to a stop in a given distance. For each, there are standards to be followed, they are different, and trying to compare them is of little value. More comparing apples to apples, landing a C 185 on wheels will have a Cessna procedure, and using that procedure, will produce defined distance results. Follow the Cessna procedure for landing the same 185 as a ski plane on snow, and the distance outcome will be much less well defined. You're not supposed to slide a tire, but slide skis to your heart's content - different standards, maybe not higher. Both the procedure and the outcome are different, but both have established procedures.
If an operator, a pilot, or a maintainer wants to
exceed a standard with great technique or skill, wonderful, but that is done while continuing to follow the procedure for the task. Sure, torque even non structural fasteners when reassembling, but you still must use the proper torque wrench, and factors for extensions, rather than making up your own home made torquing procedure. Make up new control cables instead of passing the originals yet another year, but you can't make up your own swaging procedures, you can't just use visegrips! You must use the procedure, including inspection of the swag and testing. You're doing work to a very high standard, but not deviating from accepted procedures - right?
So yes;
ANY private company can have their own "standard" , not an existing standard.
As long as the "own" standard meets or exceeds the performance requirements for that task, and conforms to approved or accepted procedures:
CAR 571.02, for a refresher:
Persons who perform maintenance or elementary work are required to follow the manufacturer’s recommendations, or equivalent practices. Where the recommendations of the aircraft manufacturer are incompatible with those of the engine, propeller, or appliance manufacturer, the recommendations of the aircraft manufacturer shall be used. Where the manufacturer has not made specific recommendations, standard industry practices are to be used. These practices include, but are not limited to, methods published by Transport Canada, a foreign Civil Aviation Authority, the manufacturer of a similar product, or other practices that may not be published provided they are generally accepted by the Canadian aviation industry. Similar requirements apply to the selection of parts, materials, tools and test apparatus.
Nowhere in there does it say "make up your own standard or procedure".