As another engineer, I also fine degree's easier to visualize than radian. But anytime I have to do theoretical mathmatics perhaps in writing an AutoCAD macro that manipulates geometry, I'm hardcore radians. But degrees make much more visual sense.
In the end, moa and milrad are simply both a measure of angle, and nothing more. The best thing to do is understand right angle trigonometry which is grade 10 math. Also realize the small angle assumption that sin x ~ x and tan x ~ x for small values of x when x is measured in radians. Since millirad scopes increment by a power of 10, and with the small angle approximation, the calculation becomes really simple, 1 millirad adjustment = 0.0001 * distance. Since our numbering system is base10, this reduces the calculation to simply shifting the decimal spot of the distance 4 spots to the right. Units are whatever you used for distance.
With moa scopes the small angle approximation can't be used. But out of lucky coincidence it turns out that 1 moa adjustment = 1.047" at 100y which almost always gets approximated to 1" at 100y. The calculation is a little more complicated espesially when placed with previous example of being off by 5" @ 800y.
But if you understand that all this is really just angle measurements and trigonometry, both are easy to use. Take the time, learn the math, and it no longer matters what you use.