I only get matchmaked against strong teams when I log out and use a guest account. As soon as I log in I am placed on strong teams versus all guest players

100% agree and have seen this first hand. 

Log into my experienced account and I get all experienced players on my team.

I immediately log into a guest account and I get paired up with all guests versus experienced players.

It has nothing to do with players teaming up, but something got changed with the matchmaking system since the last patch for the worse. Instead of balancing teams evenly it just puts all the experienced players on the top team. 

Please look into!  

When was this taken? There was a CTF bug that was giving people tons of kills points that was patched a day or two ago.

It helps if you could list names of potential offenders

I wish that were the case - the first two even said in chat they knew they were trolling.

Would that option have an effect on rankings? Methinks playing with guests might be easier to win games for experienced players

Not sure which server you are playing on, but on USA server its pretty much play with guests or don't play.

I'm sure the guests will be a temporary thing until more dedicated interest in football is established. The problem is without guests, you don't get players, and therefore you can't get anyone interested in football because there are no games. You have to start a player base somehow.