Coasting into the gate is a dumb idea at best. Never do it myself (and I'm usually a gung ho type), apart from fooling around in the sim, and in that case I shut the engines down when clearing on the high speed at 80 knots to see if I can make it to the gate.
Can it be done? Yes, absolutely, but you leave yourself potentially one failure away from no steering or brakes.
Also, the tools bragging about the accumulator, what's your recourse when the leak is in the brakes themselves, or a return line (has happened to me). On the 727 we at least have pneumatic brakes.
Additionally, when doing single engine taxi I strongly advise to keep the engine which pressurizes the HYD system on which the NWS is to be the last one shut down after a complete stop.