Aaaaaaah, I get it now. I understand what I have been unclear on. Mea culpa.
I'm not actually in need of ways to model that. My question is actually more straightforward.
Given that:
1) Proficiency bonus is a useful shorthand for the all-around competence, skillfulness, and capability of a character or creature, and
2) RAW indicates that monster and NPC proficiency bonus is based on CR, BUT
3) CR is almost entirely dependent on combat effectiveness by way of high hit points, AC, and DPR;
4) Does it make sense to treat CR and proficiency bonus as separate numbers when creating a creature or NPC that should have a high all-around indicator of competence, skillfulness, and capability whose hit points, AC, and DPR would otherwise indicate a low CR and therefore the minimal proficiency?
That's it! And the responses on balance seem to me to indicate that, no, I will not break the game by using a high proficiency bonus on a low-CR creature. So that's my issue put to rest.
Other ways to model that same thing are interesting but orthogonal to the heart of my query. But in due gratitude to the spirit in which they were offered, [MENTION=6804638]NotActuallyTim[/MENTION], you have my thanks and appreciation for the thought put into your responses, and my apologies for not making clearer that you were trying to solve a problem I don't have. Which isn't to say I might not use them anyway, a good idea being a good idea after all. Cheers!