I fly the BAe 146 and whilst doing my line training one of the trainers wanted me to have a go steering on the ground using differential brakes only. Tricky and a bit of anticipation and asymmetric thrust are required but it is possible. Took a couple of sectors until I could get it parked onto stand without resorting to using the tiller! Not ideal from a passenger comfort point of view but nice to know it can be done if you ever loose the nose wheel steering via the tiller!