Oh don’t get me wrong, pickaxe is great on Slayer too. I take pickaxe + 2h axe as my main build for Slayer. And I suppose now that you mention it Slayer probably can get comparable power, especially with 2 2h weapons.
I still really like pickaxe as Ironbreaker though. Maybe it’s just a stylistic thing, idk. The extra utility with ranged weapon support and gromril curse is nice too.
Thanks for your help guys!
Since my last post I’ve changed my build and finished Legend runs on Righteous Stand, Into the Nest and Empire in Flames, and unlike the previous build I didn’t feel like either a staggerbot or that the other guys had to carry me. I feel I’ve got a pretty good build now that works with my playstyle. Still room for improvements but I feel its more down to player skill than the build.
I’m still banging my head against the wall with the final event in Convocation but I’ve understood that’s a hard scenario so I’m opptimistic about finishing it further down the line. 
I use dual hammers on my ironbreaker for mobility without suffering crowd control. It’s non-meta but I like playing what feels comfortable to me and I’m pretty successful with them.
This is what I run on legend and cata PUGs:
Dual hammers: stamina / block cost reduction / parry
Crossbow: power vs. skaven / crit chance / scrounger
neck: health / block cost reduction / barkskin
charm: attack speed / power vs. infantry / proxy
trinket: revive speed / stamina recovery / shrapnel
I play a lot of MMOs and even though tanks in other games are really slow, that doesn’t mean you have to be in this game. I try to make my build easy for me to survive while also utilizing traits and properties to benefit my teammates as a support character. Dual hammers are already so fast that you won’t need 2 attack speed bonuses.
It really all depends on what weapons you like to use. If you don’t like a weapon, you’re not only going to be frustrated but you’re not going to be having a lot of fun either.
And for the “are you ready for legend” question, you won’t know until you try. It will be hard but try not to get discouraged when you lose a match. Practice and patience will make you better in time.
Just play around the weapons, properties, and traits. Eventually, you will find the right combination that works best for you.
Tip for Convocation of Decay: Have 1 player in the circle near the edge. The other 3 players stay below near the player who is in the circle.
This will bring all the adds to the 3 players below and the person up top will have an easier time either sniping specials or baiting them while one of the players below kills them! Hope this helps 
