I don't see it as viable for efficient farming builds. First cause it's very easy to die relying exclusively on them: If your minions are attacking an enemy ahead, an enemy which comes from your back can freely hit you. Second because they will die very often at high floors and even if you're using sacrifice for explosions effects, it's not that wondeful. Third is because ghosts generated on pack size maps: Your minions will aim at these, which is pretty annoying.
Although, I see them as very fun for playing: Summoning minions + apocalypse + fury minions for having an army is epic. If you're gonna run such thing, check out codex for "Spirit Master", "Summoner" and "Sadism" affixes. Also, there is some supporting mythics for yourself such Synergy (this one is very useful) and Summoner (mythic), Also Energy as resource system fits an build like this very well, because you won't cast too often. For increasing your damage with them you may look on "Summon DMG" and "Summon Haste" legends affixes, which don't have a cap, so you can use them as much as you want. Still about minions, you may consider +10 skill points epic affixes for increasing even more their capabilities. For rest, you still must wisely at affixes such WD+, WD%, ED%, crit chance/dmg, crushing blow, etc. and also survability affixes such dodge and block, or just HP affixes.