Occam's razor

[Sal]

a scientific and philosophic rule that entities should not be multiplied unnecessarily which is interpreted as requiring that the simplest of competing theories be preferred to the more complex or that explanations of unknown phenomena be sought first in terms of known quantities

And, William of Occam did not invent it:

https://www.merriam-webster.com/word-of-...2017-03-29

That "or that ..." seems unnecessary in my view. I've always considered Occam's Razor as the first part of the definition, that given 2 or more explanations the simplest of the explanations is preferred. Seems more like a rule of thumb than a general law of theories.

But can't it go the other way? That a theory is complex and should be considered against a simpler explanatory theory? Pilot Wave Theory springs to mind, which is widely rejected compared to the Copenhagen interpretation of QM.