you should try searching for a topic like this to answer your question, because im pretty sure that within the last three months someone has made a topic just like this.
i would tell you to just do what feels best to you, if the other team has less players but theyre all good then dont teamswitch, but if its like 3v6 and theyre getting raped then switch if you want.
or, you could just stay on your respective team and just end the game, and make sure that next game the teams dont end up stacked.