Returning to the simulation that shows that the optimal time to buy a Second Smithy is n (decksize) = 22.
In a BM + Smithy game, with no extra buys, that corresponds to turn 18 (you have 22 cards after turn 17. What this tells me is that you rarely want to buy that second smithy, in practice, since BM+Smithy buys it fourth provine at about turn 14.5 (about n= 19-20).
It's a useful metric -- inasmuch as it is another way to look at BM+single Smithy is better than BM+ 2 Smithy. By the time that the second Smithy becomes useful, the game should be out of hand in favor of BM + single Smithy.
...and that is where the mathematics come into play, imho. The "fact" of BMU making 4 provinces in about 17 turns, and BM+Smithy making it in 14.5 are the results of the math (ok... simulations). It resulted in a rule of thumb. A guideline. If you stragey can't outbuy (in total, not just provinces) BM+Smith it is inferior to it. What is your metric for that? Well, discounting chips and the other complexities of the game it is that turn 14.5 benchmark. It fits your intuition, surely, but now there is a number to your pain.
Also, there are "big money plus Smithy plus curse games". I assume that we can posit the thesis that in these games, when your deck gets to 22 cards, buying that second smithy will be worthwhile.
The concept of collision percentage is equally useful, if it can be turned into a similar guideline. I will collide 26% of the time. OK, so third f the time, I going to have this bad turn -- equivalent to a loss of tempo. Is the upside worth it? For which cards, under which types of boards? The questions are fine.. but it is the decision making framework that comes from the rules of thumb, dervied from the concepts and simulations that add to the game. Or, at least, that create structures and framworks that people can follow, and use. The beenfit of this card is (say) 1.5 whatever that means) it will colide 35% of the time, thus I roughly break even by buying it.
I'll make an analogy to the game of Bridge. It was very popular, even before the great bridge analasts of the day (1920's-30's ish, i fyou include auction bridge) and writers intorduced fairly straightforward (if somewhat flawed) and thus powerful ways to evaluate the playing strength of a bridge hand. But, by their anaysis, these writers (in this case, Milton Work) introduced the idea of the point count, and this was a guideline -- something that a beginner, with a logical mind could grasp and actually use.
Prior to that, high level hand evaluation was in the realm of the more creative mind. Point count created a framewor that people could use to compare their hands strength to baseline expectations, and then act on it.
Mathematical constructs wont answer questions like how to prepare your deck to take advantage of menagerie, but it does answer questions like how fast must I be to beat BMU-Smithy.