Degreeing a Cam, or not.....

I read somewhere that if you use the timing set that is the same as the manufacturer of the cam, it will be close OOTB.
This may be an old wives tale, but is there any truth to this? (experts)
To the O.P., the only sure way to tell where the cam is phased is to pull the front end off and the valve covers to verify where you are at.
At the same time, maybe get the other cam you were thinking of and then degree that one.
Open it up once, and then you'll know for peace of mind if nothing else..........