This is my advice to devs:
Currently sunder charms are not affecting summons. That can be fixed tho:
For example Hydra summon is kind of unique as she take effects of +%fire dmg and - enemy resist from your character, so I suggest to adjust all other summons and gave them similar aurastates based on character stats. For example Druid summons will be having new aurastate sundered take that state from your character.
Imho elemental damage benefits much more from sunder than physical.
Elemental res can so easily be refuced further (facets, items, Infy, cold mastery,…).
Physical res wil often stay at 95%. Thus, melee deal no damage.
Yes but there is not many phys immune and you have stuff like decrepify/amplify daamge and sanctuary, barb has berserk…
Barb has berserk. Thus, he does not need sunder. He basically only has the malus.
That makes mo sense. Melee builds need a freaking huge buff.
I have a legit question. Let’s say you have the bone break charm, which affects physical immunes, then cast Amp damage, wouldn’t that lower the physical res to -5% which would then be what the summons would deal with?
It lowers physical ressit to -5% just for you. For summons its only to +80%
Ah, alright then. Corpse explosion is still going to be insane if you have both the physical and fire charms, plus Amp and Infinity.
edit: My thought process was, that since Amp damage affects summons, and it is itself amplified by the charm, then the charm would affect the summons by proxy.
Just the physical charm and Amp should be enough to chain the groups.
Then again, everything worth killing is worth overkilling 
The physical alone might not one shot mobs all the time, but with both? definitely one shotting absolutely everything.
Yeah amp damage is lowering it from 95%. But honestly, there is not any Infinity like easy solution that does not make you equip certain thresher if you want to lower the phys res further.