Grant seems like a decent enough fit offensively for the Lakers, which would help justify the hefty long term investment. Lakers are one of the only teams who I saw as able to have Grant be paid his salary and be a third/fourth option.
POR gets a lightly protected FRP in the future when Lakers could be completely bottomed out, and a development guy for now in JHS. Rui is a moveable player as well if he plays well. Gabe is in for salary matching purposes and if the Blazers are trying to tank this year he helps do that while expiring 2 years earlier than Grant.