The baro altimeter has nothing to do with that particular manoeuvre. The wingtip clearance at a given bank angle can be found from the manuals, or a 'worst case' clearance could be calculated with some basic geometry. So long as the rad alt stays at or above the calculated minimum and the bank angle stays at or below the calculated maximum it's not that complex a manoeuvre. If I asked you to fly the simulator at not below 200R and not greater than 30 degrees of bank do you think it would be beyond your skills?