just to bring out some points where i had come across many a time. and to let all keep thinking...
during ATEC, both side will have umpire with them. there is this 1 time(in taiwan) where i was task to be an O/FP. i had a section plus (OPFOR) together with GPMG and my section LMG on high ground looking over a river bed. distance 800m.
the ATEC ex. troop appear on the river bed with Coy strength. this 'good' umpire come to me and tell me that if i start firing my MMG for 5min i will cause them 1 casualty. i was like

wtf.
i call in arty, take a smoke and wait... coy fast re-org after arty and carry on moving.(it was a very open area) they still have not spot my position yet. once near in 600m. i start to engage the Coy minus (due to the arty earlier.)
btw, OPFOR are using/simulate small arm of 7.62mm.
that it... the coy was like sitting duck right below me on the river bed. 600m away from me, other than the GPMG and 84mmRR there is nothing much that they can hit me with. (for ex. play, in real life i will take them out at 650m or even more if i can.)
with fire movement back to my final positions. the last man from that coy just manage to touch the bottom of my final position and it was game over for that coy.
there is no fire support for that coy at all which later i find out from the OC (he is my Coy 2IC in my last unit) his CO had told him to capture my position on his own without and fire support? wtf? just for that mission the BN fail.