The AI in R.E.D. does use units with the blitz promotion somewhat effectively (Germans), but it rarely gets united experienced and healthy enough when not German because it doesn't think strategically about where it wants to take each individual unit. Things like the 'retreat threshold' and 'anti-suicide' coding are relatively crude inflections of human reasoning. We would retreat our damaged units unless it was strategically significant to sacrifice them because we want the higher experienced unit with the more potent promotions - and we can make incredibly complex subjective adjustments to our overall strategy that can accommodate this. The normal AI was dogshit, and the R.E.D. AI is a lot better, but still no replacement for a human.
My suggestion; give the AI some super-units with IGE - armor with 20+ free promotions. that insures that they select every one. Then see how they use it.
