Re: "trying to fly on one engine would make the aircraft very difficult to control or land safely."
Maybe, maybe not.
The problem is that if the engines were at flight idle then the propellers would be at low pitch and thus very draggy, so with 3 engines in this condition and the one fully functional engine furthest from the fuselage and hence generating quite a bit of yaw control would have been pretty difficult and the sink rate would probably have been pretty high too. Add in an obstacle, and one that can ignite spilled fuel very easily and you get the result from May.
Very sad, and another example of how complex systems can do bizarre things that can't be diagnosed in the short time available. Maybe a better outcome would have required immediate shutdown and feathering of the failed engines, but the need to make that decision may not have been apparent to the crew until too late.