Missions & Complexes

2 to 3 accounts? Probably some kind of FoF missile setup. 2 or 3 sufficiently tanked Tengus/Rattlers with Friend or Foe missiles and for the Rattler geckos because those can for the most part tank almost anything lv4s can throw at you. Sentries would be another option.

It'd be horribly inefficient compared to something like a full clear + salvage marauder or Blitzing but it'd be very AFK.

imo you are better off running one account well, rather than 2-3 half assed. I used to dual box missions and issuing all the warp/jump commands multiple times was more annoying than the speed boost gained by having more dps in the mission.

if you do want to do it I'd suggest running 2-3 missions in parallel. MJD auto-targeting golem is super easy to fly, rattlesnake works pretty similar, plus gets a ton of drone dps, although with no missile velocity bonus it will lose a bunch of missile dps as multiple volleys fire at the same exploded target. Barghest also works well as it can hit at an absurd range before the next volley fires so you won't lose dps to missiles flying off into space.

command ship boosts have changed, so you have to be on grid to receive them, so an eos might be good as it can drop sentry drones and assign them. maybe a nighthawk with auto-targeting missiles?

Another idea for consideration.
I use two accounts most of the time, one fly's the combat ship while the other lags one pocket(room) behind looting and salvaging as I go.

This.

/Dual/Triple boxing missions are a matter oif taste, not efficiency. I use Machariel plus FoF missile Tengu(s) for it, FoFs attack the nearest target so I set the Tengu to approach the Mach turning it into an autonomous point defense battery that sweeps away small ships while I kill big ships with the Mach. The annoyance of having to control 2 ships is balanced by the fact that I don't have to waste drones killing small ship anymore.

The other set up I use is Mach plus Cap stable MWDing FoF missile Gila. Gila launches it's 2 drones and assigns them to assist the mach, then sets approach on one of it'sown drones. Since the Gila drones are attacking what i shoot at and the Gila is always close to it's 2 drones (meaning the FoFs are usually attacking whatever the drones are), it' turns the Gila itse'f into a 3rd Super Heavy Drone lol.

I only tend to multi box when i'm not blitzing, blitzing sucks in more than one ship, full clear missions with lots of spawns are great to dual box. Blockade is my favorite.

There isn't much benefit making them work together.
I'd be curious what you could accomplish with all 3 running missions independently. Maybe some overtanked golems to start.

Otherwise, focus 1 good runner, and make the other do something simple like mine

Ingenious :)