I really hope Duchene doesn't get moved unless some team makes an actual good offer. I don't blame Sakic for holding out. With that in mind, lines only with Duchene:
For me my lines are:
Landeskog - Mackinnon - Duchene
Wilson - Jost - Rantanen
Nieto - Soderberg - Comeau
Andrighetto - Compher - Yakupov
Duchene can take some draws on his strong side, and I see this line being dominant for most of 18minutes per night they should get.
The second line can play 15 minutes a night and hopefully Jost can handle it.
Soderberg's line should also be able to handle 12-15minutes a night.
I think Compher and Andrighetto both have a good work ethic and this would take any pressure on Yak. Its less of a 4th line and more of a limited minutes 2nd line.
This line should be solid but protected, offensive zone starts, etc for 10-12 minutes a night.
I think the D is impossible to predict outside of our top 3.