I'd rank the 5 of them, with predictions, as such at the moment....
1. Ouellet - Hockey sense is very high, great compete level, good two-way play and consistency, works hard and has noticeably good character; projects as a #2-3 two-way guy, which is where he'll eventually settle in
2. Marchenko - Very similar to Ouellet, maybe without the top-tier hockey sense, but with more reach and strength; also good compete level, two-way play, smarts, consistency, and character; projects as a #3-4 two-way guy, which is where he'll eventually settle in
3. Jensen - Top-tier speed and skating is what his game thrives on, but also works hard, has a great compete level, and plays physical; projects as a #5-6 all-around guy, will eventually settle in as a #6-7 guy
4. Backman - Yet another two-way cerebral player with consistency and good vision, but seriously lacks strength and has at times lacked confidence; projects as a #3-4 two-way guy, but will bust with the Wings and end up with another team or a career in the KHL/SHL
5. Sproul - Highest upside, lowest floor of the bunch, has great offensive instincts and a nasty shot, coupled with great size and skating mobility, but is a defensive liability who is prone to bone-headed plays; projects as a #2-3 offensive defenseman; will initially bust and end up with another team as a #6-7 guy