I think you made the right move - I don't think the overall points between the two sides will be super far off this year - you might lose out on a little bit, but you age down in a huge way without having to rebuild. I really think Backstrom's best seasons are still ahead of him, and the twins, while still great contributors, are past their peak, plus there is no telling what the switch to the Torts system will do to their numbers.
20-Team Keeper League
PTS: G=1, A=1, W=2, SO=3
Starting roster: 6F, 3D, 1G, *Keep 12 + 2 on farm
F: Kucherov, Scheifele, Eichel, Tarasenko, Rakell, Schwartz, Dadonov
D: Doughty, Josi, Ekman-Larsson, Keith
G: Hellebuyck
Farm: Tolvanen, Kaprizov
16-Team Keeper League
PTS: G=1, A=1, W=2, SO=3
Starting roster: 6F, 4D, 1G, *Keep 12 + 4 on farm
F: P Kane, Kessel, Pastrnak, Keller, Marchessault, B Schenn, Fiala, Kase,
D: Weber, Karlsson, Pietrangelo, Parayko
G: Rask
Farm: Kravtsov, A Boqvist, Necas, I Samsonov