Roslovic for a 3rd seems about right. He had two full years to make it work in WPG, didn't impress that much and then wanted out. Not a ton of value there but good on Columbus, no harm in giving him a try on a cheap contract.
Laine for Dubois is interesting. I agree that Laine is the more talented player. You look at the numbers, though, and Dubois had just 3 less points over the last two full seasons. Also scored 10 points in 10 playoff games last year. Then there's him being a centre which always seems to hold more value, but even more so for Winnipeg. They've been desperate for a #2 centre for a while and they're stacked on the wing. They knew Laine didn't want to be there long-term, and they already have a ton of money tied up in Ehlers, Wheeler and Connor. It was such a great fit that I don't think Cheveldayoff was going to push his luck by demanding another piece. Maybe he asked for it but if Jarmo says not happening, you either step away and don't get Dubois, or you pull the trigger and land a really good young piece at a position of weakness.
CLB did very well, though. Just like when they got Jones for Johansen. Jarmo was able to identify a team with a strength at one position and a weakness at another, and make the trade with them.