Your example highlighted what we learned years ago, with similar results. Now days we rarely make medibles, instead we use cannacaps. And for even more accurate dosing we use concentrates.
We do have several batches of medibles in our fridge, but they were gifts and not all that strong.
For us a large dose would be .1 gram per serving. If the rosin was 70% thc, the dose would be 70mg. And small dose would've 1/3 of that. This is obviously not exact, but it does give you something to go by.
I use 1-3 gr of concentrate per one fluid oz of coconut oil and 1/2 tsp of lecithin. This will give you roughly 30 size 00 cannacaps. We label ours by the amount of concentrate per fluid oz of coconut oil. 1x, 1.5x, 2x, 2.5x, and 3x.