I typically follow the 1-2moa prone, 2-3.5 positional.
However, I also try to design stages where those top guys are going to have targets they would have to intentionally miss; those targets aren't there for the top shooters, they are there for the low placing shooters. So this rule isn't a true "rule", it's just a guide to stick with.
Stages with large and small targets are good for this- 5 positions, two targets, one shot on each from each position. Large target is super easy- small target is rather difficult. Ensures my lower shooters won't zero out the stage. Or 10 targets at 5 ranges, large and small.
I will also run a troop line either where the near targets are like 4-5moa, and it drops down to 1 or 1.5 by the time it gets to 1k. Or I'll flip it around where the nearer targets are 1moa, maybe even ¾ moa if close enough, but the 1k target is 4moa.
Another good one is a fairly large target, with one shot from 8-12 positions. Main goal is simply to challenge my top shooters on time; I want to see about 80% of my shooters time out on the stage, with only 5-10% cleaning the stage. Those lower skilled shooters will get 30-50% of the available points. You can use this same principle by making a target rich stage where most shooters will time out before getting to the last target. Any combination of this.
You might have to just feel it out a bit. End of the day though, you have to put a lot of focus into your lower and middle range shooters; those are the ones paying the bills. It would be better that you have a match or two where it's a little too easy, than too hard. It's a lot easier to say "we'll be making the matches harder as the year goes on", than to say "uh, I kinda screwed up and made this way too hard. Sorry you 10-20 dudes shot less than 30%".
Final word of advice, not really related to target size; if you have a few really inventive stage ideas, something rather unique that you haven't seen anyone else run... First, run the idea by one or two reliable people you can use as a sounding board... Then, only put one of those stages in a match, and sandwich it between a couple solid, well liked stages. Most shooters SHOULD understand that on the club level, you might occasionally design a stage that just doesn't work out that well. They aren't going to mind too much, as long as it doesn't happen often, and everything else in the match is solid. You have to keep your matches fresh, and proofing your own stages sometimes doesn't give you an accurate feel for how your shooters will do. It happens; just be careful it doesn't happen often, and especially within the same match!