Something that has been very much in the limelight as soon as the victories aren't rolling in are de Melo's personal performances. As such I'm going to take a look at them as stats alone, which keep in mind don't tell the entire story.
Under the Luminosity banner his best notable ratings were 1.09 with a +15 K/D at IEM Katowice 2016 which the team placed second at and at Dreamhack Austin 2016 with a 1.12 and +14 K/D during the team's victory. Meanwhile his worst performances at LAN under the banner came at ESL Pro League Season 2 Finals with a 0.52 rating and a -78 K/D and 0.85 at the Faceit League 2015 stage 3 Finals with a -42 K/D, both of which were his first LAN appearances with the roster.
Moving on to SK Gaming it would be fair to say he has more LAN ratings under 1.00 than above, with his two best being 1.14 at ESL Pro League Season 6 Finals with a +31 K/D and 1.25 at ESL One Cologne 2016 with a +45 K/D. Cologne, a Major they won, actually saw him as the third best performing player at the event behind Marcelo "coldzera" David
and Nicolai "device" Reedtz
. Meanwhile his two worst were at the PGL Major Krakow with 0.83 and a -25 K/D and his very last event WESG 2017 World Finals with 0.44 and a -27 K/D.
With that being said however, I must question if the decision to make this change has come at all from the statistical performances as his ratings on LAN over his documented CS:GO career have been very similar. 2015 saw him have 0.84, 2016 saw him have 0.97, 2017 he posted 0.91 and in the past three months he has posted 0.87. This puts him at 0.92 for his career so far which isn't a world away from his current form of 0.87 for the past three months.
As I said however, stats do not tell the entire story for de Melo in particular. He describes him self very much as a support player, who will do anything required to help those around him who he knows can achieve amazing feats. Whether this means he prioritises throwing grenades to supplement his teammates peeks or puts his weaponry second in order to drop weapons to those around him. The difficulty is, whilst this is in some ways observable it is very difficult to track and display numerically for the rest of us to consume and as such, hard to quantify just how much it is worth so to speak to the team.