And you somehow got that each hit has a 3% chance of critting, which I am beyond confused about.
12% chance of Astra activating, and a 25% chance of that first Astra hit being a critical. A quarter of 12% is 3%.
They want to kill enemies efficiently and finish maps efficiently. They don't give a shit about weapon uses as those are merely means to finish the map. Astra raises the chances of killing an enemy, very valuable however somewhat unreliable, at the cost of some weapon uses, not valuable. I have never seen anyone argue that Mia and Ilyana can't get forges. I have, however, seen people say they shouldn't because they aren't good characters and aren't worth investing effort in when we could give the same effort to better characters for better results. I don't see any double standard there.
I have seen it argued before, especially that giving out any forge that isn't an axe/hand axe forge is outright detrimental. You can claim Mia and Ilyana are bad all you want, but if you have the forges to waste on Astra, you have forges to waste on Mia and Ilyana and other such characters. If you don't have the forges to give them forged weapons, you don't have the forges to waste on Astra. It's as simple as that.
And, by the way, that's a LTC standard, which makes your list invalid for anyone not playing by LTC standards and inherently unreliable.
Well from a quick glance, enemy luck ranges from 2-10, settling around 3-5 early on and 4-6 later on. The highest crit a SM can have is 29, so 27 with the lowest enemy luck. But generally, they'll have lower skill and be facing enemies with higher luck than 2. That range seems about right, but settling more in the high end.
It seems a 20-25% range is more accurate actually. Not 15-20 or 25-30.