OK.
[math]
400mp pit+100/15+280/30 bofors (18 popcap) vs 3x(no idea why you want 3 when 2 are enough, but whatever) 330mp and 200/40 as the first truck is basically free due to starting fuel and bonus menpower.
We have here 780mp and 45 fuel vs, 990mp(which again, I don't know why you insist so hard on 3 ISGs) and 200/40 med truck, but med truck is a tech building and NOT a side cost expansion, so I either need to subtract its cost completely from the comparison or add UKF T2 cost.
Lets ignore mandatory tech cost as neither med truck nor UKF T2 are optional and we'll see them every single game regardless of choices.
As shown by the supply drops, 50 fuel is worth pretty much 200 menpower so 45 will be 180mp.
This leaves us at 780/45 vs 990, which translates to 960 vs 990 mp and that 990 mp is pretty much guaranteed to hardcounter brit investment.
Now, I could recalculate everything with inclusion of tech structures AND UKF engineers(because you can't build emplacements without engies unless you go for one specific doctrine).
Either way, whether you like it or not, brits emplacements will be cleared and OKW will have considerable indirect fire force for the rest of the game. Investment in infantry force will be similar.
[/math]
Conclusion:
You've hardcountered emplacements without investing more then brit had invested in the emplacements.
The only arguable thing left is pop cap comparison, but you'll have 3 mobile light arty pieces and brit will have nothing after that.
Happy now?
Not saying emplacements are healthy or not or discussing their balance, just saying you're wrong.
Not what i meant is dat with the cancer commander the isg is not such a hard counter for the same cost
(Ty didn't know conversion fuel to mp)
And without flack HQ you can rush the isg