Hiveminds...

[Aminar]

Multiple actions are much better than zone attacks. Zone attacks just do stress, multiple actions can do anything.

True.  Especially with manuevers...  I don't know how well multiple actions can be balanced to tell the truth, but I'm sure we can come up with something worthwhile.

Taran, the spray attack thing is a really...  escoteric way to handle it.  I'd like to not stretch game mechanics too far.  We've already got a good way to limit actions by spreading out too much.  It's finding a way to allow for expanding the size of the hivemind while not breaking the character. 

[Aminar]

Bit of necessary dialogue as I think about Fate.  Hivemind characters may not take complex actions(manuevers/create advantage Actions/Blocks) without a minimum of ten minds focused on the task.  To prevent 10 attempts at creating cheap blocks and what have you.  Leaves them with attack and defend.
Another thing.
Concentration changes should probably work like shapeshifting.  Declared at the beginning of the scene and then left as is until scene change.

[Taran]

Spray attacks are not really esoteric.  They are a major mechanic of the game.

I'm just taking existing rules and applying it to the problem as opposed to making custom rules and trying to balance them.

Bit of necessary dialogue as I think about Fate.  Hivemind characters may not take complex actions(manuevers/create advantage Actions/Blocks) without a minimum of ten minds focused on the task.  To prevent 10 attempts at creating cheap blocks and what have you.  Leaves them with attack and defend.

If you use the spray attack rules, you could roll a maneuver Say you roll a total of +5.  If you have 5 groups of 2, you can do 5 1 shift maneuvers - max.  So it naturally limits the amount of maneuvers/blocks.  No need to make exceptions to rules.

I actually feel you're making it overly complicated.

[Aminar]

It's more that it isn't where the imbalance is.  It's escoteric in that it takes a function meant for a few specific instances and applies it to a whole different concept.  I honestly do see what you mean, but then they can only take one type of action at a time as well.  That's...  Out of concept.  Within the source material there are Hives of Thousands or even millions of bodies.  Entire cities are linked.  Smaller Hives work in specific functions.  Think of this like a small independent ant colony. (Noting that I make the source material...)

Sorry I'm so picky with how to work this concept.  It's a bit of a pet project...

[Taran]

Multiples of 10 would give you a higher skill rating or they'd just use team-work to create thousands of aspects to tag, so when you do you spray attack, each attack is incredibly high.

You have to break it down:
He's one character
Characters get 1 action/exchange
Characters can use spray attacks to do multiple tasks or attack multiple enemies/allies

He can pay refresh as part of his hive mind to let his spray attacks apply to pretty much every skill in his pyramid.  He can use it in multiple zones/scenes.

And like you said, if it takes 10 to make 1 character, then having only 5 would reduce his chance of success of doing to actions by half.

You don't gotta love it, but I thought it was worth defending the idea.

[Aminar]

In many ways Taran, you are right. It would be an elegant solution to the problem if it fit the flavor, and I haven't given an overwhelmingly detailed description of that flavor here.

It was definitely worth defending, and got me thinking in some different directions.  For that I thank you.
I wonder if a zone based limiter would work.  Basically, any Minds in a specific zone, due to close proximity, must work on the same task/roll.  It doesn't contradict lore(or at least the contradictions to it have their own reasons.)  So if you have Three bodies in combat, unless you really spread them out they aren't taking separate actions.  From there their own inherent aspects would likely cause them to clump together if the player is RPing them as a hive mind instead of minmaxing would act.  That gives the inherent option to pay a fate point to split things up and bonuses for sticking together throughout a scene.

[Aminar]

And now you have me thinking more Taran.  IS there a way to work multiple skill rolls off of the same dice roll via spray attacks.  Typically speaking, for point of reference it's Dice roll+skill roll, divided as the player sees fit.  If the power instead allowed a dice roll for the turn that could be divided amongst the skills being used.  The skill pyramid keeps this moderately well balanced in that most of their actions will only be Part of dice roll plus skill, but it isn't perfect.  So If the dice roll was a +2 then the hive could perform two actions 1+appropriate skill for action.  And then provide a bonus to the dice roll for the number of hive members of +1 per 10.