Would Sigurdsson be a good swap for Barkley?

Everton are looking to offload Ross Barkley for £50m and acquire Gylfi Sigurdsson for the same amount. I think it would be a shame for local born Barkley, frustrating as his unfulfilled potential can be, to leave. But in terms of Everton's playing strength I thought this made sense.

After all, with 9 goals and 13 assists, Gylfi Sigurdsson was Swansea's player of last season and was seen as one of the most productive forwards in the Premier League. But there's a but. His Opta stats show that the "expected" number of goals from his assists was 6.9. So the quality of chance he was creating was not particularly high. Here's a comparison with some rivals:

Kevin de Bruyne: Assists  18 Expected Assists  13.1
Christian Eriksen: Assists  15 Expected Assists  8.1
Gylfi Sigurdsson: Assists  13  Expected Assists 6.9

And 52 of the chances he created came from set pieces. No-one else produced more than 40. 38 of the 52 were from corner kicks. So Sigurdsson's delivery is impressive, but might owe something to the ability of Fernando Llorente and Swansea's centre backs to get on the end of them.

More than two-thirds of the chances created by Sigurdsson were headers.

There were 71 players who created more open play chances than Sigurdsson in the Premier League, including Kevin Mirallas and Ross Barkley of Everton. Ross Barkley created 54 to Sigurdsson's 25. Indeed Gareth Barry and Idrissa Gueye combined created as many as Sigurdsson. And Barkley, Mirallas and Baines, sharing Everton's set plays, created 51 opportunities last season, only one fewer than Sigurdsson.

Adam Bate of Sky Sports concluded Sigurdsson is a quality player but one who "comes with considerable caveats. Buyer beware."*

I was keen on Everton getting Sigurdsson and reaxed about Barkley going. But I thought they were like for like players. I hadn't realised Sigurdsson was a more of a successor to Baines  or even Andy Hinchcliffe.

Hmmm. Hopefully Koeman and Steve Walsh can see more than the stats indicate, but on that basis I'd keep trying to get Barkley to sign a new contract.

*http://www.skysports.com/football/news/11671/10947289/gylfi-sigurdsson-to-everton-is-the-swansea-man-value-for-money