One of the reasons that Apache won the AH competition was its enhanced survivability due to the radar (27x greater) plus its further self protection in terms of HIDAS. Once it finds its target it can then do something about it. OH58 has struggled massively with payload issues as electronics has competed with weapons in order to do something about what it finds.
If you consider crew survivability as a factor, and most pilots would, how does converting another civilian helicopter for the battlefield rate against something designed for the battlefield?
We use these machines differently as well, we dont have the numbers that the Americans have. However; what we find we can despatch quite effectively!
If we introduce another type to the inventory then we will end up with two fleets that will compete for funding and never really have enough of anything to do either one of the jobs effectively. If you purchase the same type then you will enhance the attack capability whilst retaining the good ISTAR capability it already has.
IMHO
HEDP