[FrisbeeForLunch]

Boom! (I say that when I like something cheesey ;D )

How about 3x4 instead? Save a few points (and cash) without drastically reducing performance...
Even 3x3 or 2x5 could work well, and leave you points to add troops/HQ/heavy/elite and make it a more rounded 1500pt army

[Gopesh]

I played a game against an Eldar player who did something similar. His entire army was based around 3 tanks, and the max number of walkers... (there might have been a couple other things, but that's all I really was worried about). The walkers are similar to our piranahs.

I was playing Tau. The game was over before it started. Tanks went boom in a turn or two from railguns. The mass of walkers got lit up with markerlights and rapid firing firewarriors descimated the squads in 3 turns.

When the game started, I was a bit worried, but then I thought about the numbers involved. The game was over after the first turn.

Granted the skimmers are slightly more surviveable than walkers, the rules for having squads of vehicles are so negative... they just die die die.

On the flip side, I do *like* piranahs, but for the same reason as devilfish... moveable walls with a little added firepower.

[Khathecleric]

Fully kitted out with Flechettes, these things do 5 wounds per attacking model per Piranha squadron, saves allowed, to anything assaulting into close combat. They make rather interesting anti-cc walls (that cost a bomb and still be shot to pieces regrettably. :P) so keep that in mind. Also, each squad is a 24" contesting monster, so if you've been holding them in reserve and using the PSR to delay them coming on, that's 3 zippy units appearing from the table edge for a Turn 5 contest. Usually when caught off guard (and contesting right), its very difficult to pop the entire squadron in 1 turn.

A bit of an overkill Ninja Tau tactic, but still valid.