That's what I usually do when travelling from the Nottingham area to Doncaster. I usually split at Mexborough but it's same price as splitting at Swinton.
I really do think that prices from Nottingham to major stations in Yorkshire, beyond Sheffield, are very high without splitting. That's why living north of Nottingham and close to the M1, I always use Chesterfield if travelling north.
Prices from Mansfield, 15 miles north of Nottingham, and therefore 15 miles closer to Doncaster etc are even worse without splitting! Very unfair pricing, especially if you travel the shorter route via Worksop. Its not much over 30 minutes by road!
Mansfield to Doncaster SVR is £25.50
Yet by splitting at Worksop it can be done for £15