The first point to address is, what actually is the former Borussia Mönchengladbach captain's position? Yes he plays in the centre of midfield, but in modern English football there is a few varieties of the position. Xhaka is by no means what's identified as a 'box-to-box' midfielder - like we see with Aaron Ramsey.
Although he poses a more attacking threat than new team mate, and holding midfielder, Coquelin. He has a tendency to sit in front of the centre backs and dictate play. He almost always comes short to received the ball and distributes it - acting as a vital connection between defence and offence.
Therefore I'd identify him as a 'deep lying playmaker'. Last season Xhaka rivalled Coquelin's stats for tackles and interceptions- both just under 3 per game (VIA WHOSCORED). And considering his high defence work rate, he does appear to be a viable option to play as a true 'ball winning' defence midfielder.
Xhaka has an outstanding ability to pick a pass. Anyone can go online and give him a search to see this. What interests me is his range of passes, he is capable of and consistently does make 40-60 yard passes. This offers another approach to our current play makers. At the moment the likes of Cazorla, Ramsey, Ozil and others tend to use short sharpe passes to break down the opposition.
Xhaka offers an alternative 'route one' approach that could be a refreshing change in tightly fought battles of the midfield. His direct approach could be notably useful as our wide players - Alexis, Walcott and co love to exploit space behind the defence.
It goes without saying that Xhaka is a good tackler, reads the game well and is strong in the air. However I'd like to cover a point that could go missing. At just 23 Xhaka was BMG's captain. He lead the club back into the champions league in a competitive German league and found his way into the leagues' team of the season - remarkable considering the midfield talent there is in Bayern Munich and Dortmund.
Arsenal have proven that as individuals they're some of the best in the league. But have been criticised mentally due to the lack of leadership seen on the pitch. Previous to the transfer, Xhaka has an understanding of English and will be able to communicate with his new team mates. It's hoped that he can add some leadership into the heart of the pitch and team.
Xhaka's main drawback is that he commit a lot of fouls. Although that's part of the job description, no player had more red cards in Europe's top 5 leagues. However it's widely accepted that English refs are less strict than the German's. On the other hand, one could argue that Arsenal have lacked in the physical side of the game and Xhaka's tendency for hard tackles should be encouraged.
We've shown that Xhaka offers great qualities as an individual, it's thought it this Arsenal team he'll lessen the pressure on the defence - especially in a Xhaka / Coquelin partnership. Now with his more direct approach, it's also thought he will improve the team's offence as well. So the purchase looks to be a clever one from the club as he'll improve the team on multiple fronts.
It's currently unclear what will be Arsenal's main central partnership next season. I'd imagine Xhaka would be first choice. There's two options from my point of view: Either play the two most suitable players in regards to the opposition - so Xhaka/ Coquelin for a physical battle at Stoke away, or Wilshere/ Ramsey, for example, for Villa at home where less defence is required.
Or do you try to establish a full time partnership and work on a connection between two players, seen last season with Cazorla and Coquelin. As we saw throughout 2015, an established well connect two in the heart of the team can be extremely effective in both attacking and defending.