In retrospect they were claims that I shouldn't have made that I read on the internet, which I know isn't known for being reliable.
It was my understanding that the ride was most optimal to have four trains running, not five. I don't know how management runs their trains.
I don't know the specifics of what the extra train affects, just that it has the potential to affect the show. The "greater strain" was BS on my part, as I've come to realize most of my post was pretty baseless in fact.
I didn't say my enjoyment of the attraction was impeded, but that effects like waterfalls, misters, birds on sticks, the Yeti (which yes, is only seen for a fleeting second) are either broken or turned off and have been for numerous years. Regardless, I enjoy the attraction just as much as I always have, but like a jumping Brer Rabbit, crash test barrier in Test Track, or fireworks in Muppet Vision 3D, they are not necessary for my enjoyment of the attraction but it's nice to see those effects working.
I'm simply repeating what I've seen credible posters like Lee said. I don't have any documents or have sat it on management meetings, so it wasn't right for me to make such grandiose claims.
P.S. This is the thread I read (three years ago, no wonder I don't know what I'm talking about.)
http://forums.wdwmagic.com/showthread.php?t=162472