Everyone can logically say that each player right now knows they can switch sides at will in a given moment. And that being so, the fact that under the 12 hour rule we don't see lots of players switching at one time, to say the rooks when they are steam rolling. Or to the side where the muppets are the dominant furball force wielding the pain stick.
They don't because 12 hours makes you have to stay there long past the original short term low impulse control reason justifying the country jump. There exists no easy pain free back out when the reason is over with. I suspect with side switching at will or 1 or even 2 hours, we would have had a completely different name today than vTards for 30 NOE guys magically showing up in different countries just in time to take advantage of things they spent the last 15 minutes arranging to jump countries and take advantage of.
The rule is probably not as much for the 20% who jumping for any reason to get at fights is meaningless. I know Waystin and Fish will disagree. It's for the 80% who would do it for greed, cheating like a described with the vTard example, to avoid pain, and to be with the winning team of a moment. Knowing it was at will or even 1 or 2 hours would enable the worst urges of players to rule the arena visa hoard since whizzing down your back is just as important as wining the war. 12 hours takes the place of having an army of human referees on staff to perform manual side balancing and or personal player discipline.
But, if that's what you guys really want. HTC, I have a bit of free time these days. And my wife swears I don't like anyone. Give me a list of rules and I will evenly impose them like the Borg assimilating a planet.