When you get playing in tempo with some sprightly songs, you'll find that you'll have to do whatever you're capable of to make that chord in time. That can mean playing it with one finger, two, or three. With the A in the open position there are times when you'll eventually want to accentuate only parts of it or mute the 3rd for a power chord. Feeling rigidly conformist to one way of playing it will limit you. The sun will still come up the next day and audiences aren't taking style points on chord fingerings. If it's an uncomfortable thing, don't let conformity stand in your way. (My 2 coppers). :)