For my bot team I find it useful to run one of them as a healer per se. Generally using Warrior Priest mainly or either Mercenary or Sister of the Thorn(depending on who I'm playing as). I use the Hand of Shallya trait on the neck and the AoE heal level 5 talent(being Blessed Hands for Warrior Priest). This is really useful at clearing wounds off youeself and bots if you get downed. Allowing for yourself and your bots to get down a second time and alive for longer. The Hand of Shallya and Healing talent with a medkit make for a good healing combo. As when the using a medkit on an ally, they not only get healed from Hand of Shallya for 50% of their Health, but Hand of Shallya also triggers the AoE healing Talent as well. Giving a further 20% for everyone else and clearing wounds from being downed.(all boosted by 25% if running with Sister of the Thorn) Downside is they won't generate Temporary Health(bots don't generate much anyway). But Warrior Priest can get his health back from using talents like Blazing Bright combined with The Comet's Gift. Mercenary's alt already gives Temporary Health and Sister of the Thorn leeches Temporary Health of those already full. For both Warrior Priest and Mercenary I run the Resourceful Combatant trait, in order to get their alts back quicker.
You're better off taking Necromancer over Ironbreaker, she's just as tanky with the right build. But puts out the highest damage of all the bots by a significant margin. And her skeletons are really useful in keeping enemies distracted and off your back. The build I use for the Necromancer bot is 5 Corpsemaker 10 Reaping 15 Enhanced Power 20 Cursed Blood 25 The Curse of Undead(important, must take, it's what giver her tankness.) 30 Barrow Blades Reaping, Cursed Blood and Barrow Blades make for a great combo in explosive AoE on a crit(whether it be from her melee, range or skeletons, though significantly weaker from skeletons). Reaping greatly adds to the power of this for melee crits. Making a melee crit capable of killing multiple Elites in single blow(on Legendary, seen the bot do this to patrols a few times now). Barrow Blades is important for helping igniting enemies for Cursed Blood to work As for melee weapons I find the Mace and Flaming Flail to perform the best for the her. Ranged like all of Sienna's careers, Bolt Staff is the only staff the bot will use effectively. Though you can use the Soulstealer Staff on the Necromancer for helping to ignite multiple enemies(its just not as effective at killing specials as the Bolt Staff is for her) I run both resourceful Traits on each, as it helps to get her alt back faster. Helping to keep her Skeletons up more often, which in turn helps keep her tankness up and helps keep more enemies distracted. As well as for the AoE combo. Other Careers that combo well with her are Mercenary, Witch Hunter and Sister of the Thorn(for the crit they provide. Though I generally run Warrior Priest bot as the healer for the team).
I find Into the Nest the best to run. -only rats -one of the most consistant ressource spawns in the game -free 2 dice at the end -almost always spawns a look rat Only drawback is it is a bit longer than average. For characters, I find going waystalker or bounty hunter being the best, you want to delete the elites and specials as fast as possible, your bots will stick close to you for hordes so you're being protected constantly.
