Wenger's pursuit of FC Barcelona attacker Sanchez, reportedly in a deal worth £32 million, per Jeremy Wilson of The Telegraph, is great news for Arsenal. The Chile international is exactly the kind of pacy wide forward the club needs, even over adding a new central striker.
More specifically, Ozil needs greater pace and more intelligent movement ahead of him. He didn't always have those qualities around him last season.
Long-term injuries to Theo Walcott and Aaron Ramsey robbed Arsenal's most gifted playmaker of his two best targets. In their absence, Wenger was forced to adapt.
His plan focused on packing the midfield and surrounding towering, but pedestrian, target man Olivier Giroud with cultured central players. The idea was for consistent rotation and intricate combinations to fashion chances.
When it worked, it was a joy to watch. Unfortunately, the lack of pace and natural forward-breaking instincts in Arsenal's attack showed up against better opposition.
As defensively fragile as the Gunners were in their biggest games last season, they also suffered from impotence in attack. The team was slow and static during heavy defeats to Chelsea, Liverpool and Everton.
Ozil became part of the problem. A player who is always looking to release runners with carefully threaded passes between defensive gaps, suddenly saw little options in front of him.
He was forced to play a more cautious game and retain the ball longer. That meant that everything bad about Ozil was given the chance to come to the surface.
His lack of strength and natural willingness to engage in physical battles meant he often lost the ball whenever he took his time choosing a pass. Without the moments of creative flourish to mask his languid style, the naturally sluggish Ozil often appeared lazy.
This perception has never been entirely unwarranted, but it also speaks to the kind of player fans should expect to see when they watch Ozil. His game is very much boom or bust.
For every 10 passes he attempts to skilfully steer between the lines, only a few will both reach their target and create a goal. The rest of the time Ozil's contributions will be naturally steady, patient and quiet. In other words, none of the things people expect to see from a player costing £42.5 million.
The only way for Ozil to deliver the magic more often is to surround him with better targets. That's how it worked at Real Madrid when he was the most creative player in Europe from 2010 to 2013.
Of course, back then he was aiming for forwards such as Cristiano Ronaldo, Angel Di Maria and Gonzalo Higuain. Nevertheless, the results were clear: put quick and clever moving forwards in front of Ozil, and he'll release them behind a defence.
That's what he was doing for Arsenal during his first whirlwind month in the Premier League. But that was with Walcott and Ramsey still in the starting XI.
Without them his form dipped considerably. It's a downturn that has seeped into his international career as he plays for Germany at the 2014 FIFA World Cup.
Journalist Jan Aage Fjortoft noted Ozil's struggles after Germany's 1-0 quarter-final win over France:
Ex-national stalwart Paul Breitner added his voice to those lamenting Ozil's tame showings, via German outlet TZ, per Andy Hodgson of the London Evening Standard. Criticising Ozil's effort and performances has now become a pastime all by itself.
Wenger needs Sanchez to get the best from Ozil. Sanchez has that quick, scampering speed that frightens defenders.
But just as important is the way he uses his pace. Sanchez is blessed with a knack for subtle and intelligent movement.
Whether he plays out wide, as he does for Barcelona, or more centrally, as he did at the World Cup with Chile, Sanchez knows how to take up dangerous positions.
That's because he possesses a true forward's instincts. He knows where and when chances will break his way. That anticipation, combined with pace, makes him a lethal attacker.
Sanchez hasn't always thrived at Barcelona, mostly due to the way the team funnels its play to and through Lionel Messi. But it doesn't matter where Sanchez would play along Arsenal's forward line, he'd soon becomes its focal point.
He could be a successor to Marc Overmars, a lightning-fast winger who doubles as a supporting forward. Or he could act as a Thierry Henry-style striker, at his best when roaming to and from the flanks.
With Sanchez in the team, Ozil's natural game would come to the fore more often. It's a combination that could guarantee major silverware for Arsenal this season.