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I have yet to use Piranhas within my army do to lack of experience and just plain ignorance. So, to those of you knowledge-full, when have your Piranhas really turned the tide of your war? And when would you use them, army point wise?
The Greater Good
I take one but there are several ways to use them.
One is area denial anc charge denial, buy using the relatively large footprint of several vehicles you can limit where your opponent can move to.
The other way is in singles as a tankhunter or as I found out with the fusion gun and instant killer of T4 critters like nid warriors and non-eternal characters.
Mirage Arcana Podcast
The "A Smart Player Will..." theory is a complete paradox. If we make an assumption that everything we do is outsmarted, then theoretically we can never win.
Most players use squadrons with 2 Piranhas, equipped with Fusion, TA and a disruption pod on one Piranha (if one Piranha is in cover then the 50% of the unit is in cover and both Piranhas get cover saves).
Piranhas can be used as tank hunters but to be honest I never find them that good at it. I tend to use them as opportunistic tank hunters, if the chance arises to hit a tank I will do it.
Piranhas will not do the blockading/slowing down thing effectively enough on their own, they need a couple of units of Kroot to work properly. The blockading/castling tactic works on a multi layered principle, the Piranhas are sent out as far as possible to block dangerous units, the Kroot are the next line of defence. I use a single squadron of two piranhas and two units of Kroot and I find this plenty in 2000pt games, the opponent has to get past three layers of road blocks.
Many use two or more squadrons of Piranhas but I find the benefits do not outweigh the downsides of taking more than two squadrons of two Piranhas. Like I said, Piranhas are good at what they do against the right targets but there are many many targets this tactic does not work against.
Taking two or more units means you use up the fast attack slots which means reduced numbers of (or even no Pathfinders). I take two units of 4 Pathfinders and I find the benefits of their Markerlights more useful than an extra unit of Piranhas, it also means I get two Devilfish to protect the Fire Warrior units I take. I also use the Devilfish as blockading units when needed (FW's are usually deposited in cover). Many will tell you Devilfish cannot blockade and I say bulls**t, i use em often and they do just as good a job (better in some circumstances due to that higher AV)
I would use single two Piranha unit in 1500 pts games and above but under that they are to expensive and eat into points needed for other units.
Are Piranhas game turning? No they are not, no Tau unit is. if the Tau have one overriding characteristic it is that they do not have one unit that can turn games, they are an army that uses unit synergy to be effective, basically you get nowhere relying on individual units, you only get results if you have units supporting each other.
Piranhas are decent enough at what they do as long as you recognise their limitations, oh and one last thing you really need a good understanding of the squadron rules, not only to use them effectively but also to know how to handle them if used against you. It is quite amazing how many players for instance do not realise you use the armour facing nearest to the targeting unit to work out all damage for the entire squadron, so you can have two Piranhas facing with frontal AV11 armour but the third member is closest to the targeting unit and is presenting its rear AV10 armour, all damage is resolved on the AV10. That is just one example of the squadron rules (assault is another one many do not understand) so learn the rules properly.
Haha, I expected several opinions before I found a clear explanation, but then here comes Riki swopping in to save they day! Thank you! Godspeed on your battles.
The Greater Good