It isn't trying to perform exactly the same, if it was that would be stupid.
The network and sensors are a lot closer to reality than they were before. In some cases, they are almost commercially available, but. Presumably, now it would be able to plug directly into the ABMS.
The APS would be a backup for when the superior sensors didn't identify and kill the target before it got into engagement range. Quick Kill is unworkable and completely fucked. The Trophy/Iron Fist combo APS that is supposedly in the pipeline would probably suffice. Although, it seems like that one is going to be missing for a while because Rafael and IMI had too much infighting and the Israelis didn't really have a requirement for beyond Trophy. If you have to reload the APS, presumably you would have already been mission killed at the very least.
What really killed the FCS was IEDs, which is completely near sighted.