It is a bit of a maze I'd agree. Avoid Doncaster centre, there is a huge flyover and roundabouts that are not nice. Your route avoids it nicely on the route I would take. The bit east of the A1, south of the M62, west of the A19, the Cridling Stubb-Campsall area is laney and pleasant but easy to get lost, there are unsigned roads. I would maybe stay futher west and go through Castleford, Pontefract and on to the B roads to South Elmsall, Hooton Pagnall to join your route near Donny. It's a bit more main roady though, I have not cycled on the main road south of Ponty, the A639 though so can't say what it'll be like. The road to Cas might be busy during the week too.