It may be late for this observation, I usually play around 5pm PT weeknights on the knight country. Numbers on the bish and rook start increasing for the next 3 hours on many nights with concentrated base attack initiatives. Then by 9pm PT a sharp drop off on all three sides begins to happen.
During those 4 hours, switching at will or even 60 minutes would have an impact on the current community. I venture you will see a constant shifting of a cadre of players taking advantage of everyone's initiatives. If we were back at 2007 player numbers, the numbers in the arena would tend to absorb the disruption of knowing every initiative launched will probably have a pack of scalp hunters waiting to indulge their personal desires.
And what better way to insure knowing where a herd of scalps to plunder will be, changing sides to meet the mission you just watched leave the gate. With switch at will, there would probably be three who would sit on the three different countries looking for initiatives ripe for scalping to call the rest to dinner. Even with 3 hours between side switching, I doubt it would happen because in 3 hours the action in the game changes drastically.
Switching at will being the best or every 60 minutes being almost too long, is the only solution to fulfill the personal desires of this game's cadre of scalp hunters. 2, 3, 6 hours is no different than 12 hours in the lifespan of the highly capricious instant action they are looking for. If the EW\MW arenas are any gauge for the LW low number off peak time. At will or 60 minutes for the LW would probably end up with the extremes of side imbalance you see in the other two MA.
During the low numbers time and weekends I don't know what the population numbers across the countries look like. 6 hours looks like a conservative choice to see what the damage will be over time if any. I suppose it's not the players responsibility to think about this from Hitech's PoV. Regardless of the years of complaints and forum insurrections, Hitech didn't know what the long term effect would be in a single arena LWMA. And he changed it from 12 to 6 hours during a prime arena population impact period of going into school summer break. Now school is back in session and waiting until Christmas break, even 01\01\16, is a good time frame to review the impact of 6 hours against reducing that to a smaller timeframe.
I suppose it would help if an MOTD started popping up about the 6 hour change. One thing for sure, even the closed alpha testers who have been at the testing since last August like myself, have never been told anything about what AH3 will really look like and function like on the day of the AH3 Live Rollout.