All of those factors that you list should have made it easier to subdue him. The officers came with too much force for the occasion.
I am not saying that they intended to kill him. I am saying that if you can't do your job without accidentally killing someone, maybe you should be reassigned to a desk job.
Garner was not "accidentally killed" - his death could have occurred from literally any moderate exertion: a flight of stairs could have cashed his check.
How would you have subdued him? Taser? Nightstick? What should they have done?