The fact that we have to debate whether or not Kevin Love can exist on this team is a 100% testament to how powerful the Warriors are. Against the other 28 other teams, Love is a big plus. The games where we would just rain 3's between Love, JR, Korver, and Frye were a blast. Unfortunately, the situation we're in against Golden State, Love is just not as valuable as Paul George or Jimmy Butler would be, especially with the other shooters we have on the team. The fact that Kyrie and JR are outstanding shooters, coupled with how well Lebron shot in the finals, lessens the need for Love's shooting. Against Golden State, we need more athletic and mobile players who can cause defensive breakdowns on offense. Having three world class athletes like Kyrie, Lebron, and Butler/George will not only make your offense more efficient, it will also make your defense much stronger.
I see adding Butler or George to this team at the expense of Love as a massive step forward against the Warriors. Assuming Love has neutral value against the Warriors, you could almost compare such a move to how Golden State added Durant. Durant's efficiency went through the roof in the playoffs and I'd expect Love's replacement to be the same. Granted, Durant is clearly a better player than either of them and a substantially better shooter, but the efficiency gains will be similar.
Once you have that, you can start entertaining the idea of flipping Shump and TT for Carmelo. At that point, you're doing much smaller optimizations against the Warriors. The big gain will come from flipping Love.
Games 3 and 4 showed the gap isn't insurmountable. I'd be really disappointed IF any offer for Butler or George for Love was on the table and passed on by the Cavs.