Sounds a little silly to be asking this as the hammerhead expansions come with 2 models, but I'm asking because my friend and I alr have a hammerhead exp, are considering buying and splitting another pack, so we can have 3x hh each. I would like to ask what are people's experiences fielding/fighting against a list with 3x/4x hh. Is it worth owning that 4th hh?

I own 6.

I've never had any success with them running less than 5.

From my experience and observations, If you are wanting to use them with their titles 3-6 is what makes them work.
You CAN do 2, but then that's only for people wanting them for activation padding and need the points for other stuff and not on titles.

Otherwise, nothing wrong with bringing just 1 with GH that hides in the shadows and then appears from the flanks to smash an ISD with 8 damage.

So to answer your question. 1 to 6.

I run 1 if it is crammed in Profundity.

Otherwise I run at least 4 to make the most of the excellent Task Forces

Use one as a lifeboat, like in the old days. Opponents will hate you for it, but you'll prosper.

I just received my second HH expansion for Christmas. I will be able test this question very soon... 😁

I usually run 1 or 4. I'm sure 3 could work in the right list though.

Generally my experience is that you should almost always run Hammerheads with a title, otherwise a CR90 is better unless that couple point difference between the two means the difference between cramming an activation into your list or not.

Two Slave Scout, One Exrack torp. Tfo.

Cheap and effective 3 activations.

On 12/26/2018 at 1:37 PM, Green Knight said:

Two Slave Scout, One Exrack torp. Tfo.

Cheap and effective 3 activations.

My friend kills me with these three space-holes kit out this way. 8 mostly re-rollable red die with Slaved and CF between two activations for 96 points. Then the EXRack Torp Vette to bring up the rear just to add to this mess. Then there's up to 260 points of other things left to ruin your day.

On 12/26/2018 at 1:39 PM, Green Knight said:

Use one as a lifeboat, like in the old days. Opponents will hate you for it, but you'll prosper.

Nah, that's fine....

The lack of a scatter token makes the hammerhead a lot easier to snipe at long range than the flotillas, also, it's not as cheap as the transport either.

If my opponent wants to lifeboat in a hh, I can deal with it.