“If you are struggling to fight one or two critters out in the open world with rifle or pistol, I wouldn’t suggest grenades in general to fix this, as it is IMHO even trickier to target and fire them off competently while kiting around.”
My mileage varies, I use the ‘Fast Ground Cast’ option, which casts ground based aoe directly at the cursor. (kinda like smart casting in LoL) Consequently, casting grenades while kiting only gets tricky if they -aren’t- on your rear. (then it’s a case of fighting the camera and an enemy)
One problem with this option is that it removes the ground markers, so it’s harder to get a feel for range.