Nerf the groups to do Captain Shiver in mercenary mode

I have tried get to the boss with several combos, the last 4 hours, and I end up with a half team on the first two groups no matter what group i do. My mercenary teams maxed out get one shot in round 1 90% of the time.
You have locked the weapons to mercenary heroes behind a thing you cant even reach.
I need around 7 mercs weapons still have done most of them the last week. But this one is simply impossible.
Also like each hero take 10 damage for each attack the team have done in 1 round. On my orc team that result in all mercs are dead in first round.
I have said it years back i do not like their weapons are locked behind heroic content. You do not have a good merc before their weapons are unlocked. And then hide it behind some really stupid groups on the way to the boss is bad.
I would think the bosses should be the hardest part, but in most cases its not. It’s the climb that’s the worst part. I have tried so many times today that I am about to throw my pc out the window, it really pisses me of.
Make those heroic climbs easier to do. I just quit it now again again, because of the insane difficulty the map groups have, its not even fun.
No matter how you start the fight or whatever you do they just delete your team almost instant, I even have most treasure leveled up to 10, but I do not get as far as even unlocking those.