Gotta look at it from both ends. On one hand, this will make team-shooting faster, but on the other hand, this will allow for more solo play and flanking by skilled players instead of always being restricted to having to run together with teammates who aren't always working effectively as a team. However, there's one missing component needed to make an increased TTK work: stronger abilities. Our grenades aren't as strong as they were in D1. The grenades in D1 allowed you to break up groups, or kill them, or weaken them enough to finish them off, and turn the tide when you were outnumbered. Instead of decreasing ability cooldowns, Bungie should consider buffing the melee and grenade abilities back to where they were in D1, and try balancing then from there. The Sticky Grenades, for example, could be rebuffed to reliably kill, but with no tracking to balance them. That was the main problem with those Grenades to begin with.