So lets get this straight: <...>
Total cost is 55 fuel and 430 manpower.
Now lets look at OST:
10 fuel 80 manpower: Tier 1, you know, so you can build more than a pio or an mg
40 fuel 100 manpower: Tier 2 research
20 fuel 200 manpower: Tier 2 building, plus send that pio home to go make it
60 munitions = 1 LMG on a grenadier only
Total cost is 70 fuel and 380 manpower
Don't know why you factor in t2 building. AFAIK nades and upgrades come free with T2 research.
So its 430mp 55 fuel for UKF vs 180mp and 50fuel for ost. Not accounting for 280 vs 240 mp on the unit itself.
After all this, 60 muni will make the gren outperform IS in most every situation. Beating single bren (45muni) slightly and finally loosing to double bren (at 90 muni).
Not saying the grens are better, but they are cheaper both in price and in tech with a huge power spike for little to no extra cost. They have snares on top of that and a nade with no timer (no clue why that is in the game). If someone suggest to make the IS tech more similar to grens - they should account for all the inherent bonuses as well.