Bob Tim John and Lisa all play the same basic hours. Get off work, or fart around while kids are at soccer practice or waiting for thier
dealer to show up... whatever. We'l go with 5-9 p.m. CST because that's when I usually play and no I'm not waiting on a dealer. :)

Tim is a stick to it guy. He rolls whatever and plays con-death or bust.
Lisa is a serial fort player.
John is emotionally an 8 yr old. 'Winning'=happy 'losing'=ooc meltdown acusations of cheating etc...
Bob is just moody and tempremental.

So Tim rolls an elf warrior to try out some race/classs/spec/legacy combo for kicks. goes fort because well that makes sense for him.
Lisa rolls whatever, and goes fort because she always does.
John goes empire.
Bob goes evil battle berserker.

So john get steamrolled a few times, pitches a fit and deletes.
Bob starts to get bored.
They both delete pre 30.

Bob rolls empire.
John rolls fort to be on the 'winning' side.

tim lisa and john steamroll bob so many times he deletes.
Bob gets bored irl and rolls nexus, gets bored again and deletes.
John this time doesn't delete because is is consistently on with two other people and thus 'winning'.

Bob eventually goes fort so he can play without getting gangraped every second of the day.

Now you have 4 people consistently playing the same time frame in the same cabal with no ooc communication.

Expand that to cover more scenarios and the number of actual people playing at any given time and it helps
explain the 'swing'.

I'm not saying ooc set-ups don't happen. I'm just saying other things can cause it.

I've rolled characters whose sole purpose was to affect the 'swing' and pulled it off more than once.
You can to. Roll something you want to 'have the numbers' during your time of play....
Then ... and here is the really hard part.. don't EVER delete.
Talk to every lowbie who 'might' fit into your cabal. Sell them on it.
Keep a presence up to show that Xcabal isn't afraid of the overwhelming numbers of Ycabal.
You can either run and hide and try to stay alive for as much of the time as you can or you can
con-kill yourself against the 'horde' either way make sure to keep selling the cabal dogma to
lowbies. When you are dead roll another for the same cabal, and do the EXACT same thing.
If not in the first, definitely by the second your cabal will have more numbers.
Bob and tim got bored. See? Some will have a pre-set idea of what they are rolling but not all.
You catch them early before they wrote the Mages killed my mom, evil folk killed my mom,
The lawmen are unjust, blah blah blah role, and if you didn't maybe you spark an idea for
thier next when they get sick of the bs or get bored and delete thier current.

'course I say this and I've been deleting every character for a couple of years now. hehe.
I no longer have the stomach needed to change a swing. It makes you want to scream, vomit
punch something, throw your keyboard, crawl through cyberspace and eat the face off someone
who later turns out to be either someone you are okay with or was just having a lark not realizing
that you had already been killed within 2 minutes of unghosting ALL DAMN DAY!
Wait, maybe it isn't such a good idea to try after all... hehehe. but it CAN be done.