I think this is a perfect strategy - you can sell code, and if any of it contains issues/bugs/gaping security holes you can just blame your customer for not checking the AI output
hinterlufer
For length, for an average male one meter is about one large step with extended legs (useful for distances), or the distance between e.g. the left side of your torso to the end of the extended right hand (useful for estimating the length of rope or smth).
For weight, it might be useful that 1 liter (that's 1 dm3 but noone uses that except sometimes in scientific literature) is almost exactly 1 kg, and a typical cup fits 0.25 liter. A shot of alcohol is either 20 or 40 milliliters (0.02 or 0.04 liter) depending on where you are and what you order.
For conversions you just need to remember the base unit (e.g. meter and grams/kilograms) and the decimal prefixes. But you really only need milli (1/1000), centi (1/100) and kilo (1000) in day to day life. Then you simply shift the decimal.
So, a typical pupil is around 2 mm in diameter in bright conditions. With the Rayleigh limit that results in an angular resolution of 1.22 * 60010^-9 m / 210^-3 m = 3.66*10^-4 rad
At a distance of 5 x 3 mi = 15 mi = 24.1 km this corresponds to a point to point distance of
tan(a/2) = (d/2)/l
d = tan(a/2) * l * 2 = tan(3.66*10^-4) * 24100 * 2 = 8.8 m
So in conclusion, with regular, human-like eyes he could discern points that are at least 8.8 m apart in the best case scenario. Discerning hair color from the color of the clothes would need a much higher resolution, and the horsemen are probably not 10 m apart from each other either. And again, this is a theoretical limit, real-world resolution would probably be significantly lower.
Balatro is indie, songs isn't it? Developed by a single dude with probably zero budget