I will concede that it actually didn't really occur to me the supporter counts were so low, until I started counting mine. I tend to run higher supporter counts to specifically avoid Trashalanche, which could be a trend that comes back if people get sick of it again. But then again I also refrain from running counts of cards a lot of people run - enchanced hammer is something I almost never play for example - but I can see how they would have too low of counts. In that case though I don't see any of them being viable at all except for fun, period. I'm curious about that loop you mentioned, mostly because I'm skeptical of being able to safely amass all that damage without repercussion and want to be proven wrong.Format wasn't specified, so I included Expanded.
BuzzShrine runs about 12
Malamar runs about 12
Rayquaza runs about 12
Zoroark runs about 12
and the whole format is vulnerable to Garb anyway
These decks BARELY meet the minimum. And you have to get them all removed. I don't see how that's even managable.
I agree, people do make some crazy stuff happen. I've done enough proxy testing with HAND and DAMAGE and DAMAGE is the only one I'd even consider. HAND can't work as an OTK and it's a bit counter-intuitive for a control deck. I'm not even considering MISSING. I've played a bunch of alternate wins decks in Magic and Yugioh. You need to control as much on your own end as possible to bolster consistency; when you include the opponent in the equation (in this case, your dependency on Supporters in their deck), it invites a slew of problems. And in a Regional, any opponent worth their salt will figure it out G1. 2 and 3 will be the least fun.
Where it stands right now, I don't think there's even close to enough support in Standard to build a successful MISSING deck. If you see something in it, be the change you want to see.
These 3 alternate win conditions were made to be super difficult to achieve, considering that the last one they printed was a bit easy to achieve.