I find the grenade rate is manageable so far, but the problem is that low ranked NPCs AI aim with them is about the same as a high ranked NPC aim, where expected behavior with lower ranked NPCs would be to have them misaim or have "jitter" with their grenade target locations, sometimes hitting their mark, sometimes veering off course.Uh huh.. whatever you say.. You are wrong however. Completely.. It has nothing to do with jumping around and running away.. When NPC's continually lob grenades one after the other non stop, that is a bug. PERIOD. Using them here and there or in certain situations, sure.. But just constantly throwing them without any hesitation even after they just threw one, that is a bug. PERIOD.
Regardless, if you're hiding somewhere, they will try to flush you out, and they are much more likely to use grenades if you're on a roof they can't path to, so something you can do is turn your shields on if you think they're about to start throwing grenades, which will cause them to throw shield breaking grenades, then as long as the indicator shows the shield breaking grenades, turn off your shields to avoid taking shield damage, since they don't do health damage. But be careful with this technique; if someone has line of sight to you they can still shoot you, and if an NPC has already decided to use a grenade and shouted that they're using one, they've already decided which grenade to use, so if you didn't have your shield up before they said it, a frag grenade is coming your way and you WILL need to shield that or move out of the way.