Without making the ARC infuriatingly hard to fight I don't see how you can balance it reasonably. Another part what PvP added to ARC was that you didn't want to engage the ARC unless you had to because it told everyone you where you were, it reduces your situational awareness because you're focused on the threat not the surroundings and makes you a prime target to get jumped because you're also stuck fighting the ARC. ARC left alone also turned into your alarm if someone else got caught by them.
I'm PvE nobody cares, you just blast every ARC you see because the negatives of fighting the ARC are vastly outweighed by the positives.