I've been in several games in which it is pretty one-sided, and I've been on both the receiving and the giving end of it. I tend to have very good k/d ratios, as well as a very good score rank, but this is based more off of play style and stage then anything else.
On maps like Clearcut and Sandblasted, I spend almost the entire game in a Harasser C picking off flyboys, missile boats, and the occasional potshot at 'Mechs. I often go 10(+) - 1 in games like this, and have a very good score. In maps like Inferno and Marshes, I mix it up alot with Uller A's and C's, Pumas, the occasional Hollander, and Madcat B's, and I generally still have a pretty good score and k/d ratio.
If teams are unbalanced though, I do try to balance them as best as possible, as the majority of the community is willing to switch teams if someone calls attention to it. If my team is undermanned, I call attention to it, and if the other team is undermanned, I call attention to it and switch teams. I don't know if I've ever played a game with you Mek, but if I did I hope I stayed true to what I wrote here.
Tl;dr: If teams are unbalanced, call attention to it and see what happens.