I don't see how it would hurt anything myeslf.
Just curious, do you find that you need more AP in those formations? You only get three upgrades. Every model in the crisis/FW has AP shots galore as it is. Typically, Tau players are scrounging for AT shots to get into these formations.
As far as more armor, You could already take
FW w/4DF + 2HH + 1SkyRay +
I guess you are thinking
could be 2 stingrays instead of a swordfish swap for one of the HH.(I really wish swordfish didn't swap out hh's btw!)
Personally, I don't know why you'd want it, but I don't necessarily see an imbalance issue with it.
I personally wish you could add more than just 2 HH to a formation as an upgrade.
This is really me just questing for more AT potential in the list as a whole though I suppose. Right now, the hammerheads are one of the units that are think are working... so I'd like to see more of them added to the base 'mandatory' formations. Perhaps this is not the right approach to solving the problem though.
On the other hand, it would be neat to have a hh company as a main cadre choice...
