Brown and Henrique have been effective 5v5 players that have outscored when our scoring lines are not on the ice. The Oilers have been a team that has struggled the depth on that area of the roster throughout the McDavid era.Well as of right now they haven't had Kane for the entire season and Brown + Henrique + Arvidsson + Skinner have essentially given them close to league minimum production for the price of 15M. I think that's probably a good place to start if you're looking for upgrades with moving cap out.
I don't think you're being realistic if you think we're finding more impactful bottom six players offering up closer to league minimum in lieu of the $3m-$4m the Oilers had to pursue these FAs.