Purely theorymoning here (though I will test the set soon!), but I think an LO Bulk Up set has some potential.
name: Offensive Bulk Up
move 1: Bulk Up
move 2: Ice Punch
move 3: Aqua Jet? / Waterfall?
move 4: Brick Break / ThunderPunch
item: Life Orb
nature: Adamant
evs: 32 HP / 208 Atk / 16 Def / 252 Spe
If this works for stuff like Suicune I don't see why it can't work for Arghonaut. Base 75 Speed is unfortunate, but Arghonaut gets priority so it's not all bad. Aqua Jet isn't necessary but it helps get the KO on things like Timid Zapdos. It doesn't really help much against frail sweepers though (after a Bulk Up, all its 2HKOes are OHKOes for Waterfall. See Gengar, Azelf, etc.)
The premise of the set is simple. Come in on something that can't hurt you like Blissey or Tyranitar, and Bulk Up turn one. Attack whatever comes in if you can hit it SE/if it's frail.
Ice Punch is pretty mandatory as it helps you beat Celebi and Zapdos (and Salamence). You outspeed and 2HKO Bold Celebi and Zapdos after a Bulk Up, while neither OHKO with Grass Knot/Thunderbolt respectively (However Zapdos will most likely put you into the range where LO recoil will kill you on the second attack). You can OHKO Timid Zapdos (who outspeeds you) with Ice Punch 100% of the time if SR is down. If not, then you can finish it off next turn with Aqua Jet (if you choose to run it).
The choice between Aqua Jet and Waterfall is tricky. Aqua Jet will let you finish off pokemon who are faster than you like Zapdos. However it doesn't have any merit against fast, frail pokemon as its still weak even against them.
A similar choice is with Brick Break and ThunderPunch. Brick Break lets you hit Tyranitar hard if you forego Aqua Jet, and is a harder-hitting move in general. ThunderPunch has better coverage (it hits Starmie and Slowbro who are hit NVE by every other move) and makes battles against Gyara and bulky Waters in general easier. As a note, after a Bulk Up you 2HKO Slowbro almost 99.41% of the time (though you must be wary as it can Thunder Wave you). You also do 40.10% - 47.34% to a 252/136 Impish Arghonaut, meaning you should beat every version of Argho except ones with Recover. ThunderPunch without Waterfall means you'll have a hard time against Tyranitar however, so its suggested that you pair Aqua Jet with Brick Break and Waterfall with ThunderPunch.
blah I wanted to get this up I'll get the rest in soon
EDIT- What a waste of a .5K post though V__V