Balance is very similar. You might find one to two balance poses mixed into a vinyasa class but practicing two poses once a week, in class, is not going to improve your overall balance.
You need to practice everyday. Now I am not suggesting that you have to roll out your mat everyday for an hour. There are ways to mix balance poses into your everyday life. No need to change clothes to even unroll the mat!
Every morning when you brush your teeth stand on one foot in tree pose, in the evening stand on the opposite foot.
While you wait for you coffee to brew or for the bus or the train to arrive rise up onto the balls of your feet and balance there. See how long you can stay on the balls of your feet without moving.
Balance takes practice. Don't give up! Don't label yourself "unable to hold balance poses" or convince yourself that you hate balance poses.
Simply incorporate it into your daily life.
I hope to balance with you in a class soon!