Skate skiing can give you an advantage in some cases but on steep sections and with narrow trails you need the classical. Ski-o also requires no special equipment, aside from a compass. The compass isn't so much for fine navigation as to ensure you're not making any gross directional errors. Some orienteers place their map in a special chest mounted holder, but most keep it in a plastic bag pinned to their jacket. What makes the most difference is what your head and your body have.
Equipment does play some role.
I expected well groomed trails. Instead I had to cut my own. What were tracked were narrow. Sometimes the stops are unplanned. I decided to cut between two trails.